P. Spielholz, T. Sjostrom, R. Clark, SHARP Program, WA Department of Labor & Industries, Olympia, WA; G. Kedan, B. Trenary, Intertox Inc., Seattle, WA.
Farmers are regularly at risk of exposure to oxygen-deficient atmospheres and hazardous gases such as nitrogen dioxide when working in tower silos with stored haylage. Forced ventilation using a blower, normally used to blow cut hay into a silo, is commonly used to decrease hazardous gas concentrations, and increase oxygen content within a silo headspace before entry. An investigation was initiated by the NIOSH-funded Washington Fatality Assessment and Control Evaluation (FACE) Program after a fatal incident involving two teen workers. The incident occurred in an oxygen-deficient silo, a design infrequently studied in previous investigations of silo gases. The goals of this project were to: 1) evaluate exposure to hazardous gas concentrations including low oxygen, and elevated carbon dioxide near the hatch face as it related to the incident, 2) measure hazardous gas concentrations at different levels within the silo headspace, 3) assess the efficacy of forced ventilation in reducing hazardous gas concentrations within oxygen-deficient silos. Two oxygen-limiting hay silos in eastern Washington were monitored with multi-gas direct-read instrumentation for concentrations of nitrogen dioxide, oxygen, and carbon dioxide within six days of the most recent haylage filling. Confined-space atmospheres which would not maintain life were found in all areas of both silo headspaces. Oxygen concentration returned to normal ambient levels within eight to 20 minutes from the start of ventilation. Nitrogen dioxide levels, which were only detected at elevated levels in one silo, decreased to below the short term exposure limit within 16 minutes after initiating ventilation. Carbon dioxide, which was only measured in one of the silos at levels up to 2%, cleared to less than 1% within three minutes of starting ventilation. Sampling challenges and possible error from interfering gases or aerosols will be discussed. The level of risk to farmers and practical use recommendations for dissemination to farms will be presented.
W. Sanderson, M. Madsen, University of Iowa, Iowa City, IA.
Agriculture remains one of the most hazardous industries in the United States with tractor overturns producing the greatest number of agricultural machinery-related fatalities. Rollover protective structures (ROPS) and seatbelts effectively reduce tractor overturn deaths. However a large proportion of tractors in use in American agriculture are older tractors without ROPS and seatbelts. This manuscript describes the tractor-related responses from participants in a population-based study conducted in Keokuk County, Iowa. This study was designed to measure rural and agricultural adverse health and injury outcomes and their respective risk factors. Questionnaires were partially developed from well-documented national surveys. Questions about agricultural machinery use, presence of safety equipment on the machinery, work practices, and attitudes about farm safety were included. Study participants on farms who owned tractors had an average of 3.1 tractors with an average age of 27 years. Only 39% of the 665 tractors had ROPS. Tractor age was associated with the presence of ROPS_84% of tractors manufactured after 1984 were ROPS-equipped whereas only 3% of tractors manufactured before 1960 were ROPS-equipped. ROPS-equipped-tractors were significantly more common on larger farms and households with higher income. Only 4% of the farmers reported that their tractors had seatbelts and they wore them when operating their tractors. The results of this study support the findings of other studies which indicate that many older tractors without ROPS and seatbelts remain in use in American agriculture. Until a dramatic reduction in the number of tractors in the United States operated without ROPS and seatbelts is achieved, the annual incidence of 120 to 130 deaths associated with tractor overturns will persist.
S. Reynolds, B. Cranmer, T. Keefe, J. Mehaffy, A. Serrano Martinez, R. Saito, J. Tessari, Colorado State University, Ft. Collins, CO; J. Burch, University of South Carolina, Columbia, SC; N. Koehncke, University of Saskatchewan, Saskatoon, SK, Canada; E. Wood, University of Utah, Salt Lake City, UT; L. Burch, NIEHS, Research Triangle Park, NC; P. Siegel, NIOSH, Morgantown, WV.
Gram-negative bacterial endotoxins play a key role in respiratory disease affecting more than one million U.S. agricultural workers. This project uses a novel Recombinant Factor C (rFC) assay and GC/MS to evaluate the role of endotoxin exposures and genetis in respiratory outcomes among agricultural workers. Pre-work shift measurements included spirometry, symptoms, and blood collection for TLR4 genotyping. Personal samples were collected using IOM inhalable samplers during the workshift. Spirometry and symptoms were remeasured after the workshift, and nasal lavage fluid was collected for cytokine measurement. Results from the first 55 participants are reported here. Overall inhalable dust levels ranged from 0.59 to 76 mg/m3; endotoxin levels ranged from 62 to 34,808 EU/m3. At grain elevators (n = 20) dust and endotoxin exposures averaged 12 mg/m3 and 2,803 EU/m3. Exposures averaged 4.9 mg/m3 and 5,646 EU/m3 at cattle feedlots (n = 24), 2.7 mg/m3 and 1,807 EU/m3 at dairies (n = 11). 3-hydroxy fatty acid components of endotoxin varied by operation. Baseline FEV1 was lowest for dairy and grain workers. The mean cross shift change in FEV1 was -3.1% to -3.8% for all groups. The cross shift change in FVC was greatest for dairy workers (-3.8), then grain workers (-2.1%) and feedlots (-1.8). The most common symptoms reported included eye irritation (18–42%), nose irritation (18–50%), mucous (18–42%), and cough (16–30%). Symptom rates were higher among grain workers, and lowest among dairy workers. Most participants were homozygous wildtype at the TLR4 299 and 399 loci. Exposure, cross shift changes in pulmonary function, and symptoms differed by type of operation. Exposures to dust and endotoxin were extremely high in some cases. Data collection for an additional 200 workers is planned to further evaluate the relationships among respiratory outcomes and exposures in this population.
R. Kift, S. Reed, R. Mulley, M. Davidson, Univeristy of Western Sydney, Penrith South DC, Australia.
In a sheep shearing environment there are many different contaminants that can be found in the air. These contaminants include dust (predominantly organic), bioaerosols (fungi and bacteria), and gases (e.g. ammonia and carbon monoxide). Respiratory disorders, such as chronic bronchitis and asthma, are associated with exposure to dusty conditions in farming environments. Most worldwide research within the livestock handling industries that has investigated dust exposure has been in the poultry and pig sectors. A few studies have also been undertaken on feedlot cattle. Similarly most research in Australia has also been in the poultry and pig industries, but there has been some preliminary work completed in the deer sector. Most of this research has concentrated on the health of the animals and not the health of the worker. This paper discusses the findings of a three-year study into the sheep shearing industry in NSW, Australia. Twenty-nine sheep shearing sheds were sampled for concentrations of dust (both inspirable and respirable) collected from both personal and static sampling. This study found that for dusts the average concentrations and the majority of most individual results were below either the 3 mg/m3, recommended standard for respirable dust, or the 10 mg/m3, recommended standard for inhalable dusts. A major issue is whether the current exposure standards for dusts (not otherwise classified) should be used in agricultural animal handling environments (including shearing sheds). This debate centres on the exposure to organic dusts which can contain high concentrations of microorganisms and their constituents. The current literature suggests that current exposure standards should be reduced. The results were also influenced by many different sampling variables that will be discussed.This paper presents the results from a major study into airborne exposures of dusts for workers in the sheep shearing industry in Australia.
J. Niskanen, A. Pekkarinen, Institute of Occupational Health, OULU, Finland.
There are about 300,000 reindeer in the northern part of Finland and 3,500 herders who act as private entrepreneurs. Herders work at very different types of tasks during the year. Our aim was to asses the occupational health and safety risks of different phases in reindeer herding to find out the total risk level and give information about preventive measures to the herders. The risk assessment of different work phases was carried out in three diverse districts representing the reindeer herding area. In addition to observations and interviews, we used occupational exposure measurements and results from earlier studies to verify the risk evaluation. Noise posed a substantial risk (level 4, urgent actions needed) in the stages of collecting reindeers for separation by snowmobiles and four wheelers during tasks such as feeding and herding. The yearly noise exposure of the reindeer herders was calculated to be 86 dB(A). The hand-arm vibration and whole-body vibration were also substantial risks in collection work done on four wheelers and snowmobiles. The reasons for these risks were due to the terrain and the habit of driving rather than the vehicles themselves. The risk caused by cold conditions was evaluated to be moderate in collecting, feeding, and herding tasks. The risk of insufficient lighting was moderate in the outside work during short northern winter days. Carbon monoxide was the only chemical agent causing moderate risk and only while vehicles were idle and for passenger in a sledge. The main product of the project was a safety booklet based on occupational health, ergonomic, and accident risk assessment. This booklet was written for reindeer herders in order to raise their interest and improve their safety and health at work, and to help estimate their own working habits.
C. Ballew, K. Galvin, M. Tchong, R. Fenske, University of Washington, Seattle, WA.
Agricultural workers in Washington State must deal with numerous hazards in their daily work, particularly exposure to organophosphate pesticides. These pesticides are known to cause toxic and neurological effects on the body. Individuals that are indirectly affected by pesticides are the family members who live with the agricultural workers. When the workers leave their jobs for the day, they deposit pesticides from their shoes and clothing into their vehicles and homes. This study was an attempt to estimate the amount of pesticides that workers could potentially bring into their vehicles and homes. Leaf punch samples from cherry trees in an orchard in eastern Washington were taken over a period of three weeks during the 2005 season. These were the three weeks that workers were picking cherries in the orchard. The samples were analyzed to determine the dislodgeable foliar residue (DFR) of organophosphate pesticides contained on the leaves. Crew records were obtained from the orchard manager in which were detailed each task and the duration of each task that every worker employed as a cherry picker performed during the 2005 season. Since many workers performed tasks in other parts of the orchard, such as thinning and pruning apples, spray application and crew records were used to estimate the exposure opportunity of each worker from these tasks. By adding together the exposure opportunity from both the cherry orchard tasks and tasks in other parts of the orchard, it was possible to estimate the total amount of organophosphate pesticides that each worker could bring into their vehicles and homes. This data shall be used as the basis for a new study that shall determine if orchard workers who vacuum their vehicles before leaving work bring less pesticides into their homes than workers who do not vacuum their vehicles before leaving work.
K. Galvin, R. Fenske, M. Negrete, K. Powers, University of Washington, Seattle, WA; C. Lu, Emory University, Atlanta, GA.
Families of agricultural workers are exposed to pesticides brought home on the workers’ clothing and bodies. We assessed pesticide levels in commute vehicles as predictors of home pesticide levels and if workplace factors predict pesticide residues in the vehicle and home. Pesticides studied were: azinphosmethyl (AZ), phosmet (PH), chlorpyrifos (CL), and malathion (MA). MA was applied by helicopter, and the others with airblast sprayers. Orchard workers (n=43) from eastern Washington were from three occupational groups: pesticide handlers and apple thinners from a conventional orchard, and organic orchard workers. A worker questionnaire covered pesticide safety training, clothes changing and storage, laundry, shower and hand wash facilities, and car use. Dust samples from the participants’ homes and vehicles were collected using a high volume vacuum from 1.5 m2 areas in carpeted rooms, and from the driver’s foot well. Samples were analyzed by gas chromatography. One-way analysis of variance followed by pairwise T-test comparisons with a Bonferroni correction, were used to test for differences between occupational groups. Linear regression was used to predict pesticide levels of house dust from vehicle dust, as well as pesticide levels in house and vehicle dust from occupational group and questionnaire variables. The vehicle was found to be a significant predictor of house dust pesticide concentrations for all four pesticides (p <0.01). For vehicle dust, the best model for both PH and MA contained the predictor variables,”change boots or clothes before leaving work” and, “car window open at work” as well as occupational group. For AZ, only “open window” was added. Since CL was applied two months previously, only occupational group predicted CL. For PS house dust, “changes boots or clothes” stayed in the model, and “open window” helped to predict MA levels. Based on these results, subsequent studies will assess workplace interventions to minimize exposure to pesticides.
C. Hines, C. Striley, CDC/NIOSH, Cincinnati, OH; D. Barr, A. Olsson, R. Bravo, J. Norrgran, L. Needham, CDC/NCEH, Atlanta, GA; J. Deddens, CDC/NIOSH and University of Cincinnati, Cincinnati, OH.
Acetochlor is pre-emergent chloroacetanilide herbicide used to control annual grasses and small-seeded broadleaf weeds. It is the second most abundantly applied herbicide on corn crops in the United States. Acetochlor was widely substituted for alachlor in 1990s. The US EPA has classified acetochlor as “likely to be carcinogenic to humans”; however, data on human metabolites associated with known exposure to acetochlor have been lacking. We positively identified acetochlor mercapturate (ACM) as a primary metabolite of acetochlor in all urine samples collected during a 24-hour period from custom applicators who had applied acetochlor on either the day of or the day before urine collection. Concentrations in applicator urine samples ranged from 0.5–449 µg/L (0.3–121 µg/g creatinine). Total nanomoles of ACM excreted in 24-hrs ranged from 7.71–350 nmol/24h. We observed the highest ACM level (449 µg/L) in the person who had applied the most acetochlor over the two-day period (total of 1,385 lb). Mean ACM concentrations unadjusted for creatinine for the custom applicators were up to 40-fold higher than those reported for farmer applicators. We found that ACM accounted for as much as 42% of the total acetochlor-derived metabolites in urine; however, as the exposure level decreased, ACM became a less abundant metabolite of acetochlor (17%). Unmetabolized acetochlor was also measured in the urine samples analyzed. At high exposures, acetochlor accounted for less than 1% of the total excreted acetochlor metabolites (~2% of the ACM concentrations). At lower exposures, ACM and acetochlor concentrations were similar. Additionally, we tentatively identified two other acetochlor metabolites that appeared to be important at low levels of exposure.
F. Arnold, Draeger Safety Inc., Lübeck, Germany.
The detection of fumigants is an interesting market for gas detection tubes. Because of new constraints and the decreased use of older products, new fumigants have to be developed for the future. Otherwise, a profitable production of crops, fruits and other plants is not possible.The phase out of methyl bromide especially forces the development of a couple of new gases. They have received approval in several different countries, but only a cost-efficient detection system helps to optimize the fumigation process. A new application for tubes is the testing of fumigated transport containers. There are strong regulations for the transport and treatment of wood packaging material in the worldwide shipping of goods to protect the importing countries from foreign forest varmints.After the fumigation process in the exporting harbor, the containers are purged with fresh air, and a certificate confirms the process. No labeling is required but depending on the goods placed inside the containers an amount of fumigant stays inside. When the containers arrive at their destination, the concentrations in the containers often are still above limits and are potentially dangerous for the receiving persons. Harbor workers, truckers, customs people and all others who have to open the containers for inspection may come into contact with significant concentrations of fumigants. This is an important task to measure. Some of the solutions are designed to check simultaneously the concentrations to reduce the risk of an exposure. Accidents with fumigants happen all over the world.
K. Galvin, R. Fenske, M. Tchong, University of Washington, Seattle, WA; F. Servin, Washington State Department of Agriculture, Wenatchee, WA; K. Lewis, Washington State University Cooperative Extension, Euphrata, WA; O. Borges, Domex, Yakima, WA.
Pesticide safety training is an important tool in educating pesticide handlers to have the ability to protect themselves from pesticide exposure when they mix, load and apply pesticides. The goal of this project is to transfer a research tool for assessing pesticide exposure, the fluorescent tracer (FT) technique, into a training tool for pesticide handler education. FT, a brightener added to laundry detergents that fluoresces under long-wave ultraviolet radiation (blacklight), was incorporated into the Washington State Department of Agriculture (WSDA) Farmworker Education Program’s Hands-On Pesticide Safety Training. This is a collaborative project with the Pacific Northwest Agricultural Safety and Health Center, WSDA, and the Washington State University-Cooperative Extension. During hands-on training, pesticide handlers practiced application and personal protective equipment decontamination and procedures to prevent personal contamination when applying pesticides. The training was piloted with a group of eight handlers and then conducted with a group of 24 handlers, half of whom received training with the FT and half of whom did not. Participants completed a pre- and post-training evaluation. Pesticide handlers in the FT group were impressed with the dramatic and immediate visual demonstration of potential pesticide contamination when FT was used in simulated pesticide. When viewed under blacklight, participants were able to see if they had successfully decontaminated the airblast sprayer and PPE. Handlers observed dermal exposure during casual contact with application equipment and when cleaning nozzles. They also observed clothing contamination if they did not properly remove their PPE before using bathroom. FT in hands-on pesticide safety training classes is an effective way to communicate pesticide safety. The training scenarios and technical information for using FT are being put into a manual for use by pesticide safety educators. The manual will be available in English and Spanish. Both print and Web-based versions will soon be available.
M. Tchong, K. Galvin, C. Ballew, R. Fenske, University of Washington, Seattle, WA.
One of the main concerns of agricultural workers is the possibility of exposing their children and families to the pesticides they encounter in the orchards. Agricultural workers may bring pesticides from their workplace into their homes through their clothes and shoes inadvertently. This can be considered as a take-home pesticide exposure pathway. The ideal solution is to stop the pesticides from leaving the workplace. A simple solution for preventing the pesticides from leaving the workplace will be discussed in this case study. The case study was conducted with a group of 20 agricultural workers from an orchard in Washington state. We supplied the workers with a boot bin, which was a clear, plastic box. The concept of the boot bin was to store the work boots inside the boot bin to prevent the workers from entering their homes and cars wearing their boots. At the end of the workday they removed their work boots, stored them inside the boot bin, and wore sandals to enter their cars and homes. The sandals were stored in a plastic bag and never inside the boot bin. After the workers used the boot bin daily for a six-week period, we asked them several questions regarding the boot bin. Out of 20 workers, 80% used the boot bin and 75% said it was easy to use. The workers said they liked that the boot bin helped prevent pesticides from entering their homes. A common complaint was that it was time-consuming to use the boot bin. Overall, the boot bin showed promise in keeping the pesticides at the workplace. It is portable, affordable, and easy to use. By storing their work boots in the boot bin, the opportunity for workers to bring pesticides from the workplace into their vehicles and homes is reduced.
Posted May 30, 2006