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Part 1: Intro

1 . 0 Introduction

Wood is a great of import worldwide green natural reference. Forests include about a third of the Earth , s i9000 entire property mass ( 3.

4 mil km? ). There are approximately 12, 500 species of forest, each take forthing a characteristic form of wood. ( International Firm for Exploration on Tumor, 1995 ) Wood based industry in Malaysia contains four key bomber industries. There are sawn timber veneer and panel merchandises, which include plyboard, and other reconstituted panel merchandises including particleboard, hardboard, or fibreboards, moldings, builders joinery and woodworking, pieces of furniture and household furniture constituents.

The industry is definitely preponderantly owned by Malayan and it is predicted that 80 per cent to 90 % of the companies comprise little and normal sized composition. In Malaysia, furniture makers produce a broad scope of furniture from dining room, sleeping room, home, office, infrequent, living space, upholstered household furniture or couch, outdoor and garden furniture. In Malaysia wood based industry for pieces of furniture and fixtures public demonstration, furniture sector is extremely export-oriented with more than 90 per cent of the production exported. Malaysia at this time ranked because the ten percent largest céder of furniture in the whole world and second in Asia after the People , s Republic of China, with exports to more than one hundred sixty states.

In 2008, exports of solid wood furniture amounted to RM 6. 8 billion. The primary export au finishs were the usa of America, Japan and Australia. The export worth is expected to make RM 10 billion dollars by 2010. More than eighty per cent in the furniture exported from home furniture, sleeping room furniture, upholstered with wooden body, and business furniture are made from gum elastic wood, or Hevea Brasiliensis a light colored, medium wood popularly known as “Malaysian Oak. 

As the demand to get exports of furniture enhancements, so will the production price additions, in addition to Malaysia household furniture industry, the wellness peril associated with real wood dust have yet receive coverage specifically with concern to the wellbeing of the workers and also to the environmental quality of air environing this. Wood dust is defined as any wood atoms originating from the processing or handling of forests. Wooden dust is usually generated the moment lumber is processed, including when it is damaged, sawed, switched, drilled, or perhaps sanded. ( Occupational Basic safety Health Government, 1989 ).

Wood dust particles is normally measured as air-borne atom particles concentration, by atom size distribution, by type of wood, and by different features of wooden ( Foreign Agency Analysis Cancer 1995 ). Wood dust is used to fix wooden coal, as an moisture resistant for glyceryl trinitrate, as being a filler in plastics, in addition to linoleum and poster table ( Radian., 1991 ). Another business usage to get wood dust particles is in wooden composts ( Weber ain al., 93 ). Wooden dust arises in the environment in countries where machines or tools are used to minimize or decide wood. Zero flash-point explications are available for solid wood dust. Nevertheless , wood particles is burnable and will lumination in the environment. It may show a strong to severe detonation jeopardy when a dust impair contacts a great ignition start. Wood particles is steady under typical laboratory conditions.

Exposure to solid wood dust occurs to people utilize machineries to cut or perhaps determine wooden. Deposition inside the air paragraphs depend on the scale, form, and the denseness of the dust atoms and the turbulency and rate of the air-flow. ( Worldwide Agency Research Cancer 81 ). Make use of manus held electric smoothers are referred to as a peculiarly dusty, which would decide to use exposure to real wood dust. Real wood dust concentrations vary with type of dust extraction, sum of wooden removed and type of more stable. ( Thorpe and Darkish, 1994 ). Different type of wood can besides provide forth different sum of dust. Hardwood and package are different in the physical chemical substance belongingss leading to the different in the total of wooden produced.

1 ) 1 Significance of study

The significances of this study are:

  1. To detect the degree of security and health and fitness consciousness among the list of workers of wood working to wood dust particles.
  2. To offer a extenuation attack to minimise the exposure to real wood dust through technology control and very good house preserving.

1 ) 2 Is designed of the study

  1. To measure the exposure of wood dust concentrations on layering and redirecting wood techniques in a Plastic wood home furniture mill.
  2. To suggest suitable steps to cut down wood dust particles emanation inside the furniture work.

1 ) 3 Difficulty statement

Solid wood dust is known to be a human being carcinogens depending on surveies made by Research workers from the Department of Health and Individual Services in United States and American Conference of Government Industrial Hygienists ( ACGIH ) suggested 1 mg/m? of eight hr Period Weighted Average value for any wood dust particles species. In general, exposure to inordinate sum of wood dirt is considered to support an annoyance consequence about eyes, nose area, and pharynx in addition to pneumonic map harm.

Therefore , the intent of holding a monitoring prepare is to evaluate and supervise the degree of coverage of wooden dust to the environing environment and particularly on personnel that have historical background or old record of holding virtually any related well being jeopardies to wood dirt.

1 . 4 Hypothesiss

The hypotheses from this survey happen to be:

    1. Entire real wood dust concentration and Respirable dust focus on sanding and routing methods in home furniture industry comes into the regular bound while proposed in Occupational Basic safety and Health Act 1994 by Section of Occupational Safety and Health Malaysia ( DOSH Malaysia ) which is you mg/m3.
    2. Home furniture mill get their ain basic safety steps delivered to cut down the sum of dust emitted by the use of cyclones and private Protective Products wore about workers.

1 ) 5 Circumstance survey background

The location for this survey is at Muar, Malaysia one of the most concentrated part intended for furniture manufacture industry and production of Rubberwood furniture , s. The work is situated on the 4th Great deal in Commercial Zone Parit Jamil, wherever Rubber wooden furniture merchandises such as desk leg, foundation stations, light base are created. The work itself features 100 staff, chiefly happen to be from Nepal, Bangladesh and Myanmar.

1 ) 6 Restriction of review

Questionnaire signifiers that have been given away are chiefly done in Kode Malaysia as a result of linguistic interaction restraint amongst workers via foreign says such as Bangladesh, Myanmar, Vietnam and Nepal workers in the mill.


installment payments on your 0 Launch

Forests cover about tierce of the world the Earth , s complete land country, about several. 4 , 000, 000 km2. There are 3. 5 thousand , 000, 000 M3 from the tree biomass is gathered, about half that is used as gasoline, the remainder since sawn wooden, pulpwood, plus more. ( Gichner., 1995 ). There are an estimated 12, 000 species of trees and shrubs, each deliver forthing a characteristic types of solid wood.

2 . you Definition of real wood dust

Work-related Safety and Health 1989 stated that wood dust is defined as any kind of wood atoms originating from the processing or perhaps handling of forests. Solid wood dust is definitely generated when lumber is usually processed including when it is chipped, sawed, switched, drilled or sanded. Harmonizing to IARC 1995, Solid wood dust is known as a light brown or suntan hempen pulverization. It has a certain gravitation of 0. 56. Most tree species are deciduous woods, hardwood primarily angiosperms. Basically about 800 species generally known as deal will be Gymnosperms, or perhaps cone-bearing types,. ( Bauch., 1975 )

Type of real wood

The footings “hardwood and “softwood does non needfully mention towards the hardness of the solid wood, but to the species. Hard wood is by and large denser in comparison to softwood, the place that the denseness may differ well within every single group. The scientific and common titles of a few deal and hardwood will be compiled in table you ( Vaucher., 1986 ). Wood dirt is besides characterized by the wet articles: Dry real wood ( water content less than approximately 15 % ) is less elastic than moist ( green ) solid wood, and woodworking operations with dry real wood consequence in a larger amount of entire dirt and a greater per centum of inhalable dust atoms ( Hinds., 1988 ).

2 . 2 Occupational exposure to wood particles.

Dust direct exposure occurs in a big figure of woodworking industries, where dust comes from scratch, mincing, screening or blending. Usually, wood dirt is considered being a nuisance dirt, and its inauspicious effects about open employees have simply received going to. ( W. K. Liu et al., 1985 ). Harmonizing to Jones and Smith 1986, in this 100 years, veneer- and plastic protected hardboard and fiber-board energy have been utilized intensively to get the industry of cabinets, table tops and similar and hardwood merchandises. Solid hardwoods and hardwood-veneered panels are used for high-quality home furniture because of the appealing form created by their embryon.

Wood dust particles exposure happens in primarily as an occupational publicity in some industries and businesss. The part list of open up workers involves lumbermans, sawmill workers, personnel involved in the industry of plyboard and other planks, wooden household furniture workers and cabinet shapers, workers on the market of various other wood merchandises, and glazers and joiners in the building industry. Exposure to wood dust has long been associated with a range of inauspicious health and fitness effects, which include dermatitis, sensitized respiratory results, mucosal and non allergic respiratory results, and cancerous neoplastic disease. Other symptoms associated with real wood dust publicity include oculus annoyance, rhinal waterlessness and obstructor, long term colds, and frequent worries.

The type and degree of experience of wood particles can be defined in several techniques. A first of import characteristic is the kind of wood ( hardwood, deal ) and tropical wood, or other wood varieties. Hardwoods happen to be deciduous trees and shrubs such as maple, beech, calcium supplement hydroxide, ash, birch, poplar, elm, or perhaps cherry trees and shrubs. Softwood can be cone-bearing trees and shrubs, such as fir, spruce or pine. Wood is besides characterized by the wet content, which is dependent both on the species and the quality of the wood. The attention of airborne dust is by and large measured in mg/m? with standard methods. ( IARC, 95 ) The atom size is besides an of transfer parametric amount, because the deposition form in human lower and upper air-ways partly depends on the atom size. Significant atoms ( , gt, 10m ) are regarding wholly transferred in the olfactory organ.

Researchs on wood dust believe that comparatively that few atoms larger than 5m, which type most of the solid wood dust, yesteryear into the lungs every bit far as the clearance mechanism of the olfactory organ can be non damaged. The inquiries on if wood dust particles or dust particles from one or perhaps several forests contains carcinogens have been brought up. There is no very clear reply to this kind of inquiry. An extremely big number of substance constituent can be found in wood. Cellulose, polyoses, lignin, terpene, terpenoids, fats, waxes and phenolic chemical substances such as tannic acids, yet none of them is a known carcinogen. ( Leclerc and Radiazione luminosa., 1998 )

Types of business are straight associated with the sum of exposure to wood dirt. Lumbermans and sawmill workers are exposed to relatively big atoms of fresh wood. The regular degree of solid wood dust through and large less than 1mg/m3. Solid wood furniture industry and cabinet devising involves a big physique of woodworking procedures, including sawing, organizing, come offing, sanding and usage of milling machines that produce wooden dust ( Nylander et al., 1993 ) A assortment of types are used, with predomination of hardwood for high quality home furniture manufactured by cabinet shapers, for illustration in Asiatic states. The regular size of the atoms can be particularly tiny, because the woodlands need to be genuinely dry, which usually produces seriously finer atoms and the layering, is much greater for home furniture industries, pertaining to aesthetic environment. There is a few grounds that sanding of hardwood can bring forth greater smaller atoms. ( Acheson., 1976 )

2 . 3 Sanding of wood.

Sandpapering is smoothing the surface of wood “an scratchy procedure in which borders of little, difficult, crystalline atoms happen to be quickly driven across the surface of the real wood, with push per unit area getting applied verticle with respect to the surface ( Holliday et approach., 1986 ). The smaller the scratchy atoms, the finer the dust particles produced, and the faster the smoother, the higher the total of dust particles produced. Sandpapering is the normally used arrive uping technique continuing wood coating ( Williams and Morris., 98 ). The main aim of layering is to carry out surfaces free of seeable flaws every bit good as to makes surfaces consistently absorbent for coatings ( Richter ain al., 95 )

Sandpapering is done in lots of wood companies, with very little, handheld smoothers to big membranophones or belts pertaining to smoothing a complete panel. You will discover few various ways in layering of wooden. The most common are the belt more stable, where a uninterrupted strip of emery newspaper rotated between two rollers, the dvd smoother, in which a round piece of emery newspaper fastened to a revolving disk, the membranophone smoother, where a uninterrupted secure of emery paper spun on a membranophone, and the orbital smoother, which will operates with an egg-shaped, vibrating touch. Use of manus held electric smoothers has become identified as a peculiarly dust-covered procedure, which in turn would take to exposure to dust particles. Wood dust concentrations change with sort of dust removal, sum of wood taken out, and form of smoother ( Thorpe and Brown ou al., 1995 ).

To get electrical orbital smoothers with no built-in dust extraction, complete inhalable or inspirable dirt concentrations went from 0. forty two to 8. 01 mg/m3, particles concentrations were reduced 84. 3 % to 97. 97 % when the smoothers were combined with fitted hand bags. For electric powered belt smoothers, entire inhalable dust concentrations ranged from 12. 2 to 19. 8 mg/m3 without built-in particles extraction and were lowered 66. 1 % to 93. a few % with bags. For electric orbital smoothers with external dust extraction, entire dust concentrations ranged from 0. 022 to 0. 739 mg/m3, and respirable particles concentrations ranged from 0. 003 to 0. 936 mg/m3. Rotary smoothers with external dust removal produced whole dust concentrations ranged from zero. 002 to 0. 699 mg/m3, and respirable dust ranged from zero. 001 to 0. 088 mg/m3.

A survey performed on the dirt coevals highlights of hardwoods during sanding treatment reveals that sum of wood removed during the sanding procedure predetermined dust-generation, although the wood denseness and scratchy grit utilized played an event. Consequently, low denseness wooden species created higher dust-concentration due u its comparison easiness of sanding, and vice-versa. Several sanding operations will bring forth different amount of particles concentration ( Graham and Ratnasingam., 3 years ago ). This really is proven by a survey carried on six hardwood species stand foring from the commercial perspective of transfer hardwoods utilization in Malayan real wood merchandises fabricating industry selected based on hardness and denseness as in Desk 2 . 1 )

Wood species

Common denseness ( kg/m3 )

Average firmness ( In )

Resak ( Vatica sp. )



Balau ( Shorea sp. )



Kelat ( Syzygium sp. )



Merawan ( Hopea sp. )



Rubberwood ( Hevea sp. )



Meranti ( Shorea sp. )



Table 2 . 1: Malayan Hardwood kinds used in solid wood merchandises fabricating industry. ( Taken from Dust-generation features of hardwoods during layering procedures ) Ratnasingam et al., 2009.

From the survey conducted, it is shown that the sum of real wood removed is among the most of importance factor getting dust-generation during wood layering processes. Machine sanding using belt-sanding process yielded the best dust concentrations compared to manus sanding. This is shown by important change in dirt concentration displayed in Table 2 . two below.



Dust concentrations ( mg/m3 )

Average real wood remotion ( gms )

Hand layering



Orbital sanding



Wide belt-sanding



Edge sanding


six. 5

Heart stroke sanding



Clean sanding


5. a few

Desk 2 . a couple of: Dust attention at diverse sanding methods: Taken from dust-generation features of hardwoods during layering procedures. by Ratnasingam et al., 2009.

Based on the results, about almost all sanding procedures produced dust concentration greater than the standard permitted dust direct exposure degree of 5mg/m3, proposing that sanding dust particles control features import inside the furniture fabrication industry, in the event wellness and safety criterions are visiting be achieved ( Graham and Ratnasingam et al., 2007 ).

2 . four Properties and Toxicity of wood dust particles

Wood dirt is one of the most common organic dusts workers experience in the furniture fabrication industry. ( Ratnasingam et al., 2009 ). Surveies include found that exposure to solid wood dust can easily do health and fitness effects like rhinal mucosa harm, annoyance and Sino-nasal malignant neoplastic disease, while deep lung deposition can take to lung malignant neoplastic disease and impaired respiratory map ( Shamssain., 1992 ) and ( Mikkelsen., 2002 ). Therefore a survey was undertaken to measure air-borne wood dust concentration and its atom size distribution in the Malayan Rubberwood furniture market, one of the greatest wood industry in To the south East Asia. Sampling durations of eight hours had been undertaken on the routing and hand-sanding operate Stationss to find the Time-weighted imply value of wood particles concentration.

The mean air-borne dust attention recorded to get routing job station ( 63mg/m3 ) was below the layering work station ( fifth there’s 89 mg/m3 ). This benefit was greater than the standard 8-10 hr Time Weighted Normal Maximum Direct exposure Limit intended for wood dust of 5mg/m3 ( FMR1989, HSE1999 ), and hence the high airboarne wood dirt concentration in the mills postures respiratory-related well being hazards. In footings of atom size distribution, this kind of survey revealed that less than 25 % of the air-borne dust by weight with the two work Stationss were less than 10m. Hence, the emanation during consequences suggest that simply a little area of the air-borne wooden dust atom is capable of perforating into the lower elements of respiratory system to accomplish serious wellbeing jobs. However , this review besides display that it is because of air-borne solid wood dust attention, and not the wood dust atom size distribution that posses serious menaces to the breathing of workers in the Rubberwood furniture making mills.

An additional survey performed carried out was to measure atmosphere borne dirt emanation ( 0. 1-10m ) through the routing procedure of Rubberwood ( Hevea Brasiliensis ) in the furniture industry in South East Asia. ( Ratnasingam ou al., 2009 ). The emanation of airborne wood dust during the machining of Rubberwood ( Hevea Brasiliensis ) effects in improved incidence of respiratory jobs and rhinal malignant neoplastic disease between workers inside the South East Asiatic household furniture industry ( Anon., 2008 ). Rubberwood ( Hevea Brasiliensis ) being one of the most of importance natural products for the wooden household furniture industry inside the South East Asia part, therefore the survey on the effect of dust emanation during its machining are of import about set up a benchmark for industrial well being guideline to get the Rubberwood processing industry in this part.

The consequences showed airborne particles in the opportunity of zero. 1-10m got the most terrible consequence within the wellness of workers. sixty-eight % from the workers proved as anguish from a lot of respiratory-related careers after five old age range of drawn-out exposure. The experiments confirmed that the indicate bit fullness has the best influence on dust coevals during the course-plotting operation accompanied by wood wet content and rake position. It is shown that airborne dust emanation throughout the routing treatment of Rubberwood could be reduced by striving an suggest bit density of zero. 1mm, while keeping the damp content in 12-14 % scope. These types of should remain as recommendations to reduce the airborne dust emanation, which in fold will cut down the wellness jeopardy carried by airborne dust particles to employees in Rubberwood furniture mills in Southern region East Asia ( Ratnasingam et al., 2009 ).

2 . your five Human malignant neoplastic disease surveies of wood dust particles

Recent surveies of solid wood dust

In December 2000, a study by U. H Department of Health and Man Services National Toxicity Software entitled “Report on Carcinogen for Solid wood Dust set by its drumhead statement that Wood dirt is known to be considered a human carcinogen, based on sufficient grounds of carcinogenicity via surveies in worlds. It is demonstrated through human epidemiologic surveies that exposure to wood dust enhances the happening of malignant neoplastic disease from the olfactory body organ ( rhinal pits and paranasal fistulas ).

Good and constant associations with malignant neoplastic disease with the rhinal starts and paranasal pits had been observed the two for businesss associated with solid wood dust coverage and for directly estimated real wood dust coverage. Hazards were highest for glandular malignancy, and other types of nose malignant neoplastic diseases ( squamous cellular carcinoma of the rhinal pit ) and malignant neoplastic diseases by other sites, like the nasopharynx, the voice box, and Hodgin , h disease had been associated with real wood dust exposure in several epidemiologic surveies.

The function of specific active agents of the solid wood ( certainly happening or perhaps exogenously added compounds ) in wood dust-induced carcinogenesis is ill-defined. The particulate nature of wood dirt may besides lend to solid wood dust-associated carcinogenesis since particles generated simply by wood working typically consists of a substantial proportion of atoms which might be deposited in the nasal cavity. Chronic contact with wood dust particles particulates is usually associated with lowered mucociliary clearance and improved inflammatory reactions in the rhinal pit in some surveies in worlds. In addition , cellular changes ( metaplasia and dysplasia ) observed in the rhinal mucous membrane of solid wood workers and laboratory animate beings may stand for preneoplastic provinces.

A survey in 4247 mature females used in a Norse mush and paper stock for at least one twelvemonth among 1920 and 1993, supervisory their cancerous neoplastic disease incidence coming from 1953 to 1993, supervising their malignant neoplastic disease incidence by 1952 to 1993. Compared to the countrywide female population, adult females employed for for least 3 old age range in mush and daily news work revealed an ovarian malignant neoplastic disease standard incidence rate ( SIR ) of 1. 6 ( 95 % CI sama dengan 1 . 1 to 2. 3, three or more. 1 situations ). Raised SIRs looked for chest malignant neoplastic disease and multiple myeloma in adult females with less than three old age ranges exposure, yet non for longer exposures. Not any rhinal cancerous neoplastic disease instances occured in the inhabitants. Wood particles exposure was non approximated straight, undertaking dose response hard to measure, plus the survey , s size limited it is power for most results ( Langseth and Anderson ainsi que al., 1999 )

( Imos ou al., 2k ) examined 3723 man and 3063 female employees employed for two household furniture mills in Estonia from 1946 forward, followed through 1995 intended for incidence of malignant neoplastic disease. Employees were classified as keeping low, moderate, or hi-strength of exposure based on job records. Nasal consonant cancerous neoplastic conditions were twice every bit prevalent as expected, compared with the national population, although this was depending on merely 3 instances ( all of which occured among extremely open employees. )

The lone substantially elevated hazard rose with strength of exposure between adult females, but low among work forces, use of a 20-year latency idea stengthened the association. The usage of totl chance alternatively of mortality, just good because consideration of strength of exposure and slowdown effects, were strenghts of this review. However , the sample size limited the ability to observe raised hazards of rarer cancerous neoplastic disorders. In a review conducted in genotoxicity of wood particles in a human being embryologic chest cell series, utilizing cellular civilization technique, a review on comparative genotoxic activities of two difficult jungles ( beech and walnut ) and a soft wooden ( pine ) a cell civilization with human being lung skin cells.

It is master that among the list of untreated woodlands processed in furniture industries, difficult woodlands, peculiarly beech and maple have been generally suspected to include carcinogenic belongingss in their organic components. It is often shown that beech real wood infusions induce weak mutants in bacteriums ( McGregor 1982, Mothashamipur et approach., 1986 ), an increased figure of atomic abbreations in duodenal crypts of mice ( Mothashamipur and Norpoth., 1989 ), micronuclei in rhinal epithelial tissue of mice ( Nelson et ‘s., 1993 ), and malignant tumours upon mouse tegument ( Mothashamipur et ‘s., 1989 ).

Although occupational exposure to wooden dust is encountered during all levels of wooden processing, the comparatively higher hazard of developing malignant neoplastic disease is linked to the increased level of wood dirt in the atmosphere ( Mothashamipur et approach., 1989b ). However , the strongest interactions of contact with wood dust particles and cancerous neoplastic disease development is definitely observed in businesss where merely difficult forests but simply no additives are used ( Nylander and Dement., 1993 ). The consequences of the survey present that extracts of without treatment difficult woodlands cost important chromosomal and chromatid interruptions in embryologic lung skin cells, but this kind of a sensation was not observed while using deal. A farther relative survey about DNA-strand interrupting effects of wood ( beech, oak ) and an offer ( spruce ) have been done in vitro utilizing verweis hepatocytes ( Schmezer ain al., 1994 ).

2 . 6 Surveies of malignant neoplastic disease in Experimental animate beings

Carcinogenicity of wood particles and wooden additives in rates subjected by long term inspiration.

More than 40 years ago, Macbeth reported on twenty patients with rhinal glandular cancers in the area of High Wycombe in England, of whom 12-15 had worked in the household furniture industries. Among 1967 and 1972, more elaborate information was supplied and in 1969, the tumours were acknowledged as occupational disease. Numerous epidemiological and toxicological surveies of the carcinogenic consequence of real wood dusts had been published, which in turn fundamentally verified the consequences acquired in England. In 1985, maple and beech wood dusts were grouped as carcinogenic to realms by Senate committee from the German Culture for the promotion of Scientific Analysis ( Deutsche Forschungsgemeinschaft ) in Australia, and other real wood dusts as suspected carcinogens. In 1999, hardwood dusts were classified while carcinogenic agents by the Commission payment of the European Union, on the footing of the IARC categorization of the carcinogenic strength of wooden dusts in 1995.

An investigation undertaking was initiated to measure exposures happening inside the wood market consistently, and understand better the way of development of glandular cancer from the olfactory appendage. Epidemiologic surveies were omitted, as the figure of noxious real estate agents was extremely great, and neither companies nor employees know precisely what sort of agents had been used, even though the type and additives such as varnish, discolorations, gums and wood chemical preservatives that are used happen to be known, frequently the pretreatment of the solid wood is not known Long-run trials in which animate beings were exposed to motivation seemed to be a suited method, provided that the malignant neoplastic diseases seen in worlds could be induced in research laboratory animate creatures under similar conditions. Because the Numberss of providers was extremely big intended for systematic showing in this kind of experiments, short-run surveies of toxicity and genotoxicity had been carried out to operate as a ground for the design of long term trials.

Material used inside the survey incorporate Oakwood dust particles, because it is one of the most genotoxic with the wood tested, the genotoxicity was examined with cyclohexane infusions. Solid wood preservatives adding lindane and pentachlorophenol ( PCP ), because lindane was genotoxic in human nasal cellular material. Chromate can be besides used, which is genotoxic, includes drawn-out rhinal expulsion and, when ever used in wooden preservatives, may take to dysplasia. Chromate provides often been used in the wood-processing sector, peculiarly while K bichromate in discolorations but besides as a restore agent in wood additives

A group exposed to N-nitrosodimethylamine ( NDMA ) served while positive handles, because rats exposed to certain nitrosamines happen to be known to develop tumours of the rhinal hole. Exposure and animate getting handling were performed harmonizing to the The german language Law on the Protection of Animals. The exposure tracts of mice to real wood dusts and wood additives are so that all the coops of all seven experimental groupings were rotated daily in their exposure containers, harmonizing into a strategy recorded for each group and 24 hours. The moment all revealed animate creatures are considered collectively, the consequences proceed even more obvious. Fatal breathing piece of land tumours occurred in the five of 155 rouse,stimulate beings exposed to oak solid wood ( G = 0. 08, Fischer trial, in comparison with the adverse control ), in five of 102 animate creatures exposed to chromate ( P = 0. 03 ) and in two of 101 arouse, rouse, stimulate beings confronted with lindane and PCP ( P = 0. seventeen ) when such tumours were no seen in the 96 adverse controls.

These measurings inside the terminal perform non enable a decision about the magnitude to which chromate histories to get the effects linked to exposure to walnut and beech wood dust or to get the epidemiologically ascertained local fluctuations in tumorigenesis. Even more wood types from various parts will hold being analyzed intended for chromate and compared.

2 . 7 Minimizing dust emanation by the usage of tool angles.

Dust created in the engineering of wood is a key job in the on the job environment. Minute real wood atoms carried through the atmosphere make an important wellness jeopardy, in maximum instances even taking to malignant neoplastic disease. In wood working industrial sectors, it has demonstrated a peril to employees wellness, specifically in the signifier of cancerous neoplastic disease of the sinus and paranasal fistulas.

A sum-up of probes of wood particles and the threat of malignant neoplastic disease can be found in Nylander and Dement ( 1993 ), where writers claims that magic formula agents inside the wood working sector face a higher hazard of developing rhinal malignant neoplastic disease, particularly those working together with machines that generate solid wood dust. A great experimental study did simply by J. Palmqvist et ‘s., 1999 around the influence of cutting explications and application geometry in cut downing dust emanations at the beginning, that is certainly at the suggestion of the device.

Method suited for three distinct wood stuffs such as, pinus radiata, beech and fiberboard ( MDF ). Specimens were processed within a miling devices where it had been possible to improve the film editing infos. The dust particles emanations from your tool ( defined in this article as atoms with a size less than 10m ) had been measured. The parametric amounts altered in the experiments were moisture articles of the solid wood, mean little bit thickness, technique of provender ( up or down ) and rake angle of the tool. The experiments revealed that the indicate bit density had the highest influence for the sum of dust produced when engineering wood and wet articles of the solid wood, a reasonably superb influence, and while the way of the provender and and the profligate angle got small or no influence.

The effects show that dust emanations increase quickly when making a particular mean little thickness. It is hence of import to cipher and command the mean tad thickness in order to minimise the dust emanation between the 3 wood tested.

2 . almost 8 Routers and Sanders basic safety jeopardies

Routers are used for this kind of intents just like cutting and determining beauty pieces, doing frame and panel entry doors, and miling moldings.. The tool-spindle axis is normally verticle with respect, but it may be tilted. The operator lessens the caput for engineering, and the caput automatically comes back to their original place after the slice is made. Providers may be harmed from random contact with the routing device when taking care of stock or perhaps taking little bit from the listar array. Kickback is another prevalent beginning of hurt among routers operators. Projections of tools can badly twisted or get rid of router employees. Tools may be flung in the cutter caput if they are sick fastened in the tool holder, if the incorrect tool is employed, or if the tool speed is excessively high ( A usher pertaining to protecting employees from woodworking jeopardies, 1999 )

Router with Adaptable Tool Protect should be accustomed to protect the routers by serious harm that is caused by crisp instrument in knife vesica. Additional that it, equip routers which has a spindle braking system that bit by bit engages. Inside the average show, some tips about safe operate patterns just like properly add and protected toolsto the holder, and label cutting tool and holders while using maximal allowable spindle speed. Drum sanders are people who finish inventory by utilizing a coated scratchy surface to consider stuff. A belt more stable uses a devices of obstructs to travel scratchy stuff accross the stock. Either the wood is usually fed personally or instantly into the machine or the sanding belt can be pressed toward the real wood, which is situated on a working listar array ( A jason derulo for safeguarding workers coming from woodworking jeopardies, 1999 ).

Drum sanders produce a serious considerable measure of all right wooden dust. Almost all smoothers should be carefully ventilated. The primary security jeopardies of belt smoothers us that workers may possibly catch all their custodies, vesture or jewellery in the working axial shifts. Safety job patterns ought to be to replace lacerate, frayed, or exessively put on belts or membranophones. A raddled belt, disc or membranophone may do a monolithic heat accumulation, which can do the belt, disk or membranophone to rupture or disrupt and overwhelm the environing country having its projected spots. It is besides of transfer to maintain custodies off from scratchy surfaces and sand around the downward-moving part of the disc or belt.. ( A usher intended for protecting staff from woodworking jeopardies, 99 ).

Chapter 3: Strategy

3. zero Entire dirt aggregation utilizing MiniVol Portable Air Sampler.

The MiniVol Air Sampler is an ambient air flow sampling stop for particulate affair and non-reactive gas. The patented low flow engineering used in MiniVol was developed with each other by the U. S Environmental Protection Agency ( EPA ) as well as the Lane Regional Air Pollution Power in an attempt to consider the demand pertaining to portable air pollution trying anatomist. MiniVol gives consequences close to about as in mention quality of air informations. Equally precise and accurate, the battery controlled, lightweight MiniVol is ideal for trying at far away countries or station net. The MiniVol can be designed to try for a comparable mention station web.

Inside the particulate affair ( PM HOURS ) seeking manner, air flow is driven through a atom size centrifuge and so by using a filter channel. Particle size separation can be achieved by impaction. Actual volumetric flow should be 5 litres per minute ( 5 L/m ) in ambient conditions. Impactors can be obtained with a 10-micron cut -point ( PM10 ) and a 2 . 5-micron cut-point ( PM2. 5 ). Operating the sampling place without an impactor allows for assimilation of whole suspended affair ( TEASPOON ). a couple of unit of Minivol is employed in this starting. Both assumptive account is taken to site and operated at a few litres each minute. First theoretical account of Minivol can be found sanding region where there were two layering maestro machine and random orbital sanding procedure is usually taking topographic point. Second theoretical account of Minivol is situated for country of where routing of wood is usually taking topographic point.

This kind of research was carried out in three hebdomads in the month of The fall of and Dec 2009. Total suspended atom ( TEASPOON ) was collected from this two station. The location to place the Minivol unit was chosen depending on the work procedures which produce more dirt. First stop, in routing procedures, particles produced by the routing devices are coarser and more dirt are accumulated by the pump. In the next station, solid wood sanding process by devices and manus is the job processes which were assessed. Sandpapering utilizing equipment are done to smoothen the portion of furniture which is not even in order to do the household furniture finer in quality which can make it an improved market value.


  1. Sampler: 47-mm PVC, 2-5m pore size membrane or tantamount membrane filtration and back uping tablet in 47mm cassette filter holder.
  2. Minivol Air testing station
  3. Microbalance, capable of weighing to 0. 001mg.
  4. Forceps ( sooner nylon )

Preparation of filters.

  1. Equilibrate the filters within an environmentally handled weighing country or chamber for at least 2 hours.
  2. Number the backup parts with a ballpen pen and topographic stage them, numbered side down, in filtration system cassette bottom subdivisions.
  3. Excess weight the filter systems in an ecologically controlled region or holding chamber. The filtration system tare fat are record, W1 ( milligram ).
    1. No the balance just before weighing.
    2. Manage the filtration systems with forceps.
  4. Put together the filtering in the filter cassettes and close tightly so that the get away around the filter will no happen.


  1. Calibrate every single Minivol unit with a rep sampling train station in line.
  2. Test at 5 L/min for any entire test of 12 L. Perform non surpasse a entire filter burden of about two milligrams whole dust.

Sample readying

  1. Wipe dust in the external surface of the filtration system cassette which has a damp paper towel to minimise ruin. Discard the paper towel.
  2. Remove the best and bottom stoppers from your filter softly to avoid decrease of dust.

Calibration and Quality Control

  1. No the microbalance for evaluating. Use the same microbalance pertaining to weighing filtration before and after test aggregation.


  1. Weigh each filter. Record the station sampling pounds, W2 ( milligram ), in the air volume level sampled. Record anything novel about the filter paper ( electronic. g., excess, escape, wet torn, and so forth )


  1. Calculate the concentration of Entire dust particulate, C ( mg/m3 ), in the air volume experienced, V ( L ):

C = ( W2-W1 ) ( milligram ) Volt: ( F1 + F2 ) x T

Versus ( L )

Period Leaden Typical, TWA:

Net dust weight ( milligram )



Flow charge ( L/min ) by 0. 001 ( m3/L ) ten clip ( min )


3. one particular Respirable particles aggregation making use of Personal Air Sampling Pump ( PASP )

Respirable dust may be the fraction of the complete dust that enters the gas exchange part of the lungs. 2 unit of personal sampling pump suited for two specific workers which may have lasting function displacement. The trying pump is worn on the neckband of the personnel shirt, and is also fastened with a limiter. Sample pump that was used through this research is through the theoretical bank account Apex HB 3294-04. It uses an efficient end pump whose flow charge is exactly maintained utilizing an automatic flow control circuit. The pump draws contaminated surroundings through a sample caput at a rate determined by the caput design and style or attempting scheme.

The Apex originated to supply trying capablenesss among 5 ml/min and a few l/min, fitted to a broad opportunity of applications including solvent exhausts, the product clearance and private sampling of dusts. Apex pumps happen to be ideally suitable for many of the Total and Respirable dust striving techniques detailed in U. K Health insurance and Safety Business publication MDHS14, and in additional mention strategies. The seeking pump functions at 2 . 2 L/min for Higgins-Dewell cyclone, pertaining to 8 human resources daily for 3 hebdomads, by 8am to 5pm, operating clip in the mill. The employees are chosen based on the wood operations that they do. The mill does non give the workers revolving occupation mundane, therefore it is better to try on one person for the whole twenty-four hours making the same improve an usual of eight hours.

Respirable dust much more of the quantity of dust that goes in the gas exchange portion of the lung, therefore it is a really of import index of how the lung system can be troubled by utilizing this kind of instrument.


  1. Testing station:
    1. Filter: 5. 0 m pore size, polyvinyl chloride filter or perhaps tantamount hydrophobic membrane filter supported by a cassette filter holder
    2. Cyclone: 10-mm synthetic, Higgins-Dewell ( BGI Inc., 58 Guinan St . Waltham, MA 02153 ) ( 7 ) or tantamount.
  2. Personal Sampling pump, 2 . two L/min + 5 % for HIGH-DEFINITION cyclone with flexible relating tube.
  3. Stability, analytical with sensitiveness of 0. 001mg.
  4. Forceps ( sooner nylon )
  5. Environmental chamber or perhaps room for balance.

Preparation of filters.

  1. Equilibrate the filters within an environmentally managed weighing country or chamber for at least 2 hours.
  2. Number the backup pads with a ballpen pen and topographic level them, numbered side straight down, in filtration cassette bottom level subdivisions.
  3. Pounds the filtration in an ecologically controlled region or step. The filter tare excess weight are record, W1 ( milligram ).
    1. No the balance prior to weighing.
    2. Manage the filters with forceps.
  4. Set up the filtration in the filtration system cassettes and close firmly so that the avoid around the filtering will non happen.
  5. Remove the cyclone , s grit cap before usage and inspect the cyclone inside. If the home is visibly scored, fling this cyclone since the dust particles separation popular features of the cyclone may be improved. Clean the within the cyclone to forestall entrainment of big atoms.
  6. Assemble the sampling train station caput. Verify alliance of filter holder and cyclone in the attempting caput to forestall break free.


  1. Calibrate each personal sampling pump to the appropriate flow level with a agent sampling station in line.
  2. Test 45 minutes to 8 hr. Make not transcend a few mg dirt lading on the filter.

Sample readying

  1. Remove the top and bottom stoppers from the filtration cassette. Equilibrate 2 hours in an environment controlled nation or step.

Calibration and Top quality Control

  1. Weigh every filter. Record this post-sampling weight, W2 ( mg ).


Estimate the concentration of Complete dust particulate, C ( mg/m3 ), in the air quantity sampled, Sixth is v ( T ):

C = ( W2-W1 ) ( mg ) Volt: ( F1 + F2 ) by T

Sixth is v ( L )

Time Leaden Typical, TWA:

Net particles weight ( milligram )



Flow rate ( L/min ) back button 0. 001 ( m3/L ) eight clip ( min )


3. 2 Data Analysis.

The consequences is usually analysed utilizing Independent examples T-test upon both Total dust benefit and Respirable dust worth. The consequences infos collected pertaining to Entire dirt and respirable dust in station one particular and station 2 attention is besides analyzed using Mann-Kendall Trend analysis. Mann-Kendall tendency research is a nonparametric trial pertaining to indentifying inclination in clip series annonces. The trial compares the comparative magnitudes of sample explications instead than the informations principles themselves. ( Gilbert., 1987 ). 1 benefit of this kind of trial is usually that the informations require non adapt to any distinct distribution. Furthermore, informations reported as non-detects can be included by delegating them a common value that is smaller than the actual mensural value in the data set. The procedurethat will be described inside the subsequent paragraphs assumes that there exists simply one annonces valueper cut period. Once multiple annonces points are present for a specific clip period, the average benefit is used.

several. 3 Questionnaire on Occupational exposure to solid wood dust.

The level of exposure to wood dust is definitely observed by using a list of set of questions to the believed 30 % of entire personnel in the work. The study was distributed to 30 employees who be employed by full shift of almost eight working hours for the same everyday work techniques in the mill. Due to linguistic communication hurdle among the personnel from overseas states such as Bangladesh, Nepal, Vietnam and Indonesia, the questionnaire may merely be taken through Kode Malaysia as the chief moderate.

The questionnaire distributed contains 3 parts, where initially portion protects the personal information ( butir-butir peribadi ) of the employees such as the gender, age, pounds, tallness, contest and on the task clip. That besides includes on the earlier business of workers, the length of time have they work in the current generator and in the yesteryear of the same quality. Separate two screens for the past job topographic level status, environmentally friendly scene by which they operate, and apart from the erosion of private Protective Equipment such as mask, safety boots, matched working outfit, safety glasses.

Part 3 screens all their on the job position in their current work topographic point. Same inquiry while proposed to portion a couple of, but an accessory smoke will not during operate clip, and besides current industrial pattern on the hygiene of dirt emanation. A sum of 30 questionnaire were allocated to the personnel involved in the generator chosen employing workers which might be straight involved in this study, that is redirecting and layering procedures. Outcomes from surveys takers are utilizing a great analytical device called Record Package intended for Social Sciences ( SPSS ) type 17. zero.

3. some Location of survey

This survey is carried out in Muar which can be The town of Muar is found at 23? N10234? At the, at the mouth of the Muar River. The town is about a hundred and fifty kilometers ( 93 stat mis ) sou’-east of Malaysia , s capitalKuala Lumpur, regarding the same range ( 179 kilometer ) northwest ofSingapore. It is 45km south ofMalacca Town. It is besides 60 kilometers north ofBatu Pahat.

Beginning: www.maps.google.com.my Figure a few. 1: Area of Muar, Johor.

The mill is situated at Parit Jamil commercial zone, Muar. There are 75 workers in production line based in the mill, in which 60 % are foreign workers coming from Vietnam, Nepal, Bangladesh, Indonesia, Myanmar and local Malaysian. The generator operates by Monday to Saturday apart from public getaways and Saturday. There are five section which includes Management squad where all of the wood is process by simply modeling, deciding, routing to finally carry out out a all right quality furniture. Here are some of the statistics of wood procedures that are done in the mill.

Part 4: Consequence AND DISCUSSION

4. 0 Independent trials T-test upon Total dust particles for layering and course-plotting.

The amount suspended atoms informations collected for course-plotting and sanding procedures in the two Stationss was assessed utilizing SPSS for 3rd party samples T-test on Total dust to get the two impartial variables, sanding and course-plotting. The chief purpose of operating the information making use of T-test is usually tests the value of the big difference between the two sample companies.


Nothing at all: the imply of two group are non substantially different

Surrogate: the agencies of the two group happen to be significantly several


Depending on Table four. 1, the standard value of 1. 6645mg/m3 intended for sanding techniques is above 1 . 5051mg/m3 from course-plotting procedures. This means that on norm, sanding method output larger entire particles concentration than routing method in 17 workers from both Stationss. Therefore depending on the average effects, the void hypotheses is accepted.

Table 4. you: Group figures for Total Suspended Debris in sanding and course-plotting.




Standard Deviation

Standard Error Mean

Quantity Suspended Atoms



1 . 5051

. 92566

. 22451



1 . 6645

. 74017

. 17952

T-Test for Total suspended atoms.


you: Sanding and routing techniques have about equal discrepancy on the dependent variables.

two: Sanding and routing methods are impartial on one one other.

Based on Desk 4. 2: The consequences pertaining to Levene , s trial for equality of discrepancy is that we accept the first assumption that is layering and redirecting procedures have got about the same discrepancy because the value of significance is usually 0. 557 which is higher than 0. 05. Therefore the two discrepancy value is not significantly distinct.

Table four. 2: Levene , t Test intended for equality of discrepancies intended for Total Hanging Particles.

Levene , s Test out for Equal rights of Discrepancies



Sum Hung Atoms

Similar discrepancies believed

. 353

. 557

Equal differences non believed

In the Table four. 3, Impartial samples of t-test shown in equal discrepancies assumed via Levene , s trial, it can be conclude from the big t value of -0. 555 with class of independence 32, for important degree of 0. 05, there is no important difference involving the sanding and routing types of procedures. The quantity of Entire dust manufactured in the sanding procedure is usually non significantly different from complete dust by routing treatment. Entire particles is collected from the particles that has gathered in the ambient air, so that it can not be scored specifically that beginning the dust is definitely coming from. Wind flow way, relative humidness and various work commencing done in same station might impact the motion with this all right dirt atoms traveling approximately in the air.

Table some. 3: Self-employed samples t-test for Total Suspended Contaminants

t-test for Equal rights of Means




( 2-tailed )

Average Difference

Sum Suspended Atoms

Equivalent discrepancies believed

-. 555


. 583

-. 15941

Equal discrepancies non presumed

-. 5iphon scam

30. 523

. 583

-. 15941

4. you Independent Samples T-test on Respirable dust particles for sanding and redirecting.

Based on stand 4. 5, the average benefit of some. 4865 pertaining to sanding methods is more than 2 . 7509 from routing procedures. This kind of mean upon norm, repirable dust about workers is higher in the sanding techniques than routing procedures.

Desk 4. 4: Group statistics for respirable dust about sanding and routing method.




Standard Deviation

Standard Problem Mean




4. 4865

1 . 83743

. 44564



installment payments on your 7509

. 81998

. 19887

Based on desk 4. your five, for respirable dust, the two groups that may be sanding and routing provides about equivalent discrepancy intended for the two based mostly variables. As well as the consequence demonstrates the important value is greater than 0. 05 which is zero. 260 meaning that they are low significantly several.

Table 5. 5: Levene , t Test intended for equality of discrepancies to get Respirable dirt

Levene , s Test to get Equality of Discrepancies




Equal differences assumed

1 ) 316

. 260

Equal discrepancies non thought

In table some. 6, through Levene , s trial that the discrepancies are about equal, t value of 3. 557 with 32 grade of independence, at 0. 05 essential degree, it shows that there exists important diverse in the total of repirable dust by routing and sanding treatment. Respirable dust is the total of particles measured inside the take a deep breathing zone of the workers, this means it can mensurate the amount of dust particles that is inhaled into the lung by require a breathing the air indoors. This can be an of import indicant to trial how much several wood working procedure produces distinct consequence about workers.

Desk 4. 6th: Independent examples t-test to get Respirable dirt

t-test for Equality of Means



Sig. ( 2-tailed )

Average Difference

Std. Error Difference



The same discrepancies thought

3. 557


. 001

1 . 73559

. 48800

Similar discrepancies low assumed

3. 557

twenty-two. 130

. 002

1 . 73559

. 48800

4. two Mann-Kendall Trend analysis of entire dirt.

Wood dust particles informations gathered during three or more hebdomads of monitoring can be divided into two Stationss of wood treatment, that is real wood sanding and routing method. The entire dust collected pertaining to 3 hebdomads is tested to see the correlativity between the clip puting and variables pertaining to sanding and routing treatment.

Based on stand 4. 7, the Mann-Kendall tau correlativity coefficient is definitely 0. 603. This positive value display an increasing trend to Total particles value intended for sanding place.

Table four. 7: Mann Kendall analysis for correlativity trial entire dust station1.

Kendall , s tau Correlation Test

ALL OF US Geological Survey, 2005

Datas set: Case in point Totaldust values , Mann-Kendall trial, suggestions type four

The tau correlativity agent is zero. 603

S i9000 = 82.

omega sama dengan 3. 337

P = 0. 0008

The relation may be described by the formula:

Y = 0. 43264 + zero. 1206 5. Ten

To back up this kind of consequence, depending on figure 4. 1, it might be seen that there is a essential addition to get the 2nd hebdomad ( fourteenth Dec to 19th Dec 09 ) during this show period, the concentration of entire particles rise from 1 . 995 mg/m3 to 2 . 175mg/m3 ). To get the undermentioned hebdomad, twenty first Dec 09 to twenty sixth Dec 2009, there is a crispy addition in twenty-four hours 4 of reading, around the 23rd December 09, the worth recorded was 3. 804 mg/m3. This kind of unusual reading may come as a consequence of the air current velocity, weave way and sum of wood being sanded through the entire twenty-four several hours.

There is a reducing of 2. 286 mg/m3 for the last two 24 hours of monitoring. The sums of wood dust concentration have decrease due to alter in air current velocity and comparison humidness inside the ambiance. High value of comparative humidness can easily do the air going even more concentrated with all the dust atoms and when air current produces, it provides the particles around the environmental air in the mill. An additional factor that contributes to the high emanation of dirt in the sanding procedure in station one particular in the third hebdomad of monitoring is a result of the usage of devices particularly the use of two sanding maestro equipment which is operated at different velocity and due to the distinct sum of dust generated by distinct wood usage, its hard to command the emanation of dust personally by utilizing vacuity or cleaning the floor. This might therefore possibly do the operate topographic stage dustier and difficult to maintain it clean.

Based on table 5. 8: the Mann-Kendall tau correlativity coefficient is zero. 691. This kind of positive value shows an increasing tendency for entire dirt in stop 2 . In the meantime, at zero. 05 guarantee interval, possibility of 0. 0001 which means there may be important difference in the worth of solid wood dust in station a couple of reading every bit good.

Desk 4. 8: Mann Kendall analysis intended for correlativity trial on Entire dust station 2

Kendall , s tau Correlation Test

US Geological Survey, 2005

Datas established: Example Totaldust values , Mann-Kendall trial, input type 4

The tau correlativity coefficient can be 0. 691

S sama dengan 94.

tissot = three or more. 831

S = zero. 0001

The relation may be described by equation:

Sumado a = 0. 74132 & 0. 1287 *


The graph displayed in Figure 4. a couple of is supervised in train station 2 . The graph reveals a positive embrace hebdomad you, hebdomad a couple of and hebdomad 3 of monitoring. In hebdomad 1, the value of whole dust does non increase significantly nevertheless on hebdomad 2, there were steadily maximize over the whole hebdomad and this form continue until hebdomad 3 where the highest examining is on the 22nd December 09, 2 . 270 mg/m3. The lowest benefit was recorded in 18th November 09 where reading is definitely 0. 561 mg/m3. The consequence demonstrated in the graph comparing to find 1 is non as important in station 1 .

This is because in station 2, the entire dirt concentration inside the ambient air is afflicted with the usage of operating expense steaming system wherever it is used to hoover away all the particles generated by simply machines and in each compartment, there are besides less particles accumulated through the work topographic point.

some. 3 Mann-Kendall tendency evaluation on respirable dust.

Desk 4. being unfaithful shows the consequence final product for respirable dust about electrical orbital sanding process. The tau correlativity coefficient is 0. 463 and this suggests that there exists a positive elevating tendency proven in orbital sanding.

Stand 4. 9: Mann Kendall analysis for Respirable dust on wood sanding method.

Kendall , t tau Correlation Test

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