Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “worker”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,009 records · Page 56Linked to original sources
PubMed1991

Exposure-related declines in the lung function of cotton textile workers. Relationship to current workplace standards.

To evaluate the effectiveness of the current workplace standards in preventing chronic health effects from cotton dust exposure, a 5-yr longitudinal study of a large multimill population of cotton textile and synthetic process workers, employed at a major U.S. textile company, was conducted. To control for and assess the effect of type of work area on annual change in lung function, we limited the analysis to those 1,817 subjects who, throughout their textile work history at the company, worked exclusively in cotton yarn manufacturing or slashing and weaving, or in synthetic textile mills. The expected effect of smoking on average annual change in lung function was demonstrated for both cotton and synthetic workers. Despite lower overall dust exposure, cotton yarn workers exhibited steeper annual declines in lung function than did workers in slashing and weaving; this difference persisted within each smoking category, indicating a dust potency effect. There were mill differences in annual change in lung function among cotton workers, potentially masking an exposure effect. A smoking-work area interaction persisted after adjusting for mill differences, with the largest annual declines observed in cotton yarn workers who smoke. A significant dose-response relationship was seen in cotton yarn manufacturing between annual declines in FEV1, FVC, and FEF25-75 and average exposure by mill, and the larger declines were found in mills using the highest percentage and lowest grade of cotton. Synthetic textile workers had larger declines than did cotton textile workers, which were not explained by smoking or duration of employment. Unrecognized and unmeasured causative exposures or selection bias could explain this result.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1981

Pulmonary function loss in Vermont granite workers. A long-term follow-up and critical reappraisal.

Previous studies of Vermont granite workers averred that pulmonary function loss was occurring at 2 to 3 times the normal rate. The excess loss was attributed to the current, relatively low concentrations of dust prevailing in the stone sheds. Because the Vermont State Health Department had traditionally provided surveillance of granite workers to detect evidence of occupationally related illness, we offered pulmonary function screening to any currently employed worker. Spirometric data from the first 150 workers, compared with data from the previous studies, showed a large increase in the FVC and a smaller increase in the FEV1. We therefore undertook a survey of the entire stone shed work force, as well as of retired workers tested previously. The results in 487 current workers indicated an overall increase in FVC from 1974 to 1979 of 0.540 L, and an increase in FEV1 of 0.030 L: predicted losses based on the previous studies were 0.350 to 0.400 L in FVC and 0.250 to 0.350 L in the FEV1. Analysis of data in various subgroups, such as retired workers or those with more than 20 yr of work experience, also showed increases in FVC, and either slight gains or minimal losses in FEV1. The possible reasons for apparent improvement in pulmonary function are discussed. We concluded that technical deficiencies in the previous studies led to exaggerated and erroneous estimates of loss. At this time, the actual decrement in pulmonary function values for exposed granite workers is not known and requires further investigation. Because the newly proposed, stricter standard, for silica was importantly influenced by the previous studies, we believe that adoption of this standard would be premature.

Air Pollutants↗
PubMed1981

Distinguishing byssinosis from chronic obstructive pulmonary disease. Results of a prospective five-year study of cotton mill workers in India.

This prospective 5-yr follow-up study of 1,241 textile workers from three mills was designed to determine the pattern and course of byssinosis in India and to distinguish this disease from chronic bronchitis. The initial prevalence of byssinosis was 14% in carding sections, 10% in spinning sections, and 11% in winding sections. In these dusty sections, the prevalences of both byssinosis and bronchitis increased with a longer service. Among workers with byssinosis; 56% had work-related and exertional dyspnea, 54% had chest tightness, 20% had wheezing, and 36% had cough. There was a history of Monday sickness in 22%. During follow-up it was confirmed that the atypical presentation of byssinosis with cough was more common in the carding department. The yearly decrease in pulmonary function was correlated with duration and degree of exposure to cotton dust. Thus, the decrease was larger in carding workers and in workers with byssinosis plus cough than in those with byssinosis or bronchitis. The yearly decrease in the one-second forced expiratory volume was different (p less than 0.05) for subjects with nonspecific chest symptoms (88 ml) and subjects with work-related chest symptoms (114 ml). The decreases in forced vital capacity and one-second forced expiratory volume were larger for increased dust loads. Fewer pulmonary infiltrates were seen in radiographs of workers with byssinosis than in those of workers with bronchitis. The immunoglobulins studied in 86 textiles workers and 17 control subjects showed higher IgG values among workers with work-related symptoms, especially cough, but not among those with bronchitic symptoms (p less than 0.01). Our results suggested that byssinosis is an entity distinct from chronic bronchitis.

Adult↗
PubMed1996

Worker participation in an integrated health promotion/health protection program: results from the WellWorks project.

According to prior reports, blue-collar workers are less likely to participate in worksite health promotion programs than are white-collar workers. This study examined worker participation in the WellWorks worksite cancer prevention intervention, which integrated health promotion and health protection. Analyses were conducted to assess relationships among participation in health promotion and health protection programs, and workers' perceptions of management changes to reduce potential occupational exposures. Results indicate that blue-collar workers were less likely to report participating in health promotion activities than white-collar workers. A significant association was observed between participation in nutrition- and exposure-related activities, suggesting that participation in programs to reduce exposures to occupational hazards might contribute to blue-collar workers' participation in health promotion activities. Furthermore, when workers were aware of changes their employer had made to reduce exposures to occupational hazards, they were more likely to participate in both smoking control and nutrition activities, even when controlling for job category. These findings have clear implications for future worksite cancer prevention efforts.

Adult↗
PubMed1995

Health status of cement workers in the United Arab Emirates.

The aim of this study was to investigate some of the health problems among cement workers in the United Arab Emirates (UAE). A cross-sectional sample of 304 workers was selected randomly from four cement factories in four Emirates. Most of the workers (88%) were from India, married (84%) and had received primary education or above (93%). Smoking was prevalent among 27% of the workers and about 24% consumed alcoholic beverages. Personal hygiene was found to be satisfactory among the workers. The main health symptoms reported by the cement workers were chronic cough, chronic bronchitis, burning, itching and runny eyes, headache and fatigue. Chronic bronchitis (p < 0.007), burning, itching and runny eyes (p < 0.002) and fatigue (p < 0.004) were significantly increased with age of workers. Smoking was significantly associated with chronic cough (p < 0.03) and chronic bronchitis (p < 0.01). However, the chance of smokers getting respiratory health problems was two to five times greater compared with non-smokers. Future studies on the health of workers in UAE should include more investigations using specialised equipment to detect and diagnose health problems.

Adult↗
PubMed1996

Occupational health status of sawmill workers in Nigeria.

The health impact of exposure to sawdusts on 59 sawmill workers from southwest Nigeria was studied. Workers were chosen by a two-stage random sampling method from 15 privately owned sawmills. Peak flow and spirometric measurements were obtained from all workers. They also underwent a structured questionnaire which elicited occupationally related symptoms. Age and sex matched controls consisting of 199 workers from similar socio-economic backgrounds as the subjects underwent similar questionnaire and lung function tests. Results showed a high prevalence of respiratory symptoms, principally cough, chest pain and sputum production, among the workers. Most of the workers also had high prevalence of conjunctivitis, skin irritation and hearing difficulties when compared with controls. Pulmonary function parameters were also significantly lower (p < 0.05 in sawmill workers than controls). Although a large number (94.9%) of the workers were aware of the potential hazards of exposure to sawdusts, less than 20% wore protective masks. Our study highlights the need for health and safety regulation in the workplace. There is also a need for improved methods of dust control in factories with high levels of dust particulates, particularly in the developing world.

Adult↗
PubMed1998

Respiratory symptoms and lung function in garage workers and taxi drivers.

The aim of this study was to determine the prevalence of some respiratory symptoms and possible diseases among occupationally-exposed garage workers and taxi drivers. This study involved 158 garage workers and 165 taxi drivers, matched for age, sex, nationality and duration of employment. The mean age of 158 Indian subcontinent garage workers was 34.4 +/- 10.4 years; their mean height and weight were 167.7 +/- 6.6 cm and 72.0 +/- 12.3 kg respectively, and the mean duration of employment garage workers was 8.8 +/- 7.6 years. The mean age of 165 Indian subcontinent male taxi drivers was 34.5 +/- 7.7 years; their mean height and weight were 168.7 +/- 6.1 cm and 71.3 +/- 12.6 kg respectively; and the mean duration of employment was 7.5 +/- 5.4 years. The data on chronic respiratory symptoms showed that garage workers had higher prevalence of symptoms than taxi drivers being significantly greater for chronic phlegm, (p < 0.007); dyspneoa (p < 0.001); and sinusitis (p < 0.03). A higher prevalence of all acute symptoms was recorded in garage workers than in taxi drivers, although the differences were significant only for throat (p < 0.02), hearing problems (p < 0.002); nose (dryness, bleeding and secretion) (p < 0.008); and low back pain (p < 0.05). Almost all forced spirometric tests in the exposed garage workers were lower than in taxi drivers. The results of stepwise multiple regression analysis showed that only phlegm, sinusitis, hearing problems, nasal catarrh, throat, low back pain, smoking and FEF25-75, variables were statistically significant predictors as risk factors. In conclusion, the present study suggests that a high prevalence of respiratory symptoms is associated with exposure to motor vehicle exhaust emission in garage working places. Long-term working as garage workers in the United Arab Emirates (UAE), may be associated with the development of chronic respiratory symptoms and have effects on their daily life and health.

Adult↗
PubMed1997

A Study of the Health of Seafaring Workers of Valencia, Spain.

Under the auspices of the Service of Maritime Health of the Marine Social Institute of Valencia, Spain, the health status of seafaring workers from Valencia was evaluated. An epidemiologic study was carried out based on 707 pre-embarkation health examinations, collecting information about the health problems of these workers and their associated risk factors. The data were analyzed to estimate population frequencies and the corresponding 95% confidence intervals. Significance among groups was calculated by the chi-square test (p < 0.05). Relative risks were calculated in comparisons of the seafaring workers with the general population of Valencia. High incidences of ophthalmologic disorders were found in workers over 50 years of age (15.9%) and in alcohol consumers (29.3%). Digestive problems were observed among alcohol-consuming (21.7%) workers 31-40 years old (8.5%). Risk factors for circulatory disorders increased steadily among those over age 50 (9.0%), non-smokers (10.3%), and those weighing more than 75 kg (8.2%). Finally, respiratory diseases were more frequent among individuals whose work involved fishing (12.7%). Risks increased with alcohol and tobacco consumption (16.6% and 17.5%, respectively). The risks of developing circulatory and ophthalmologic disorders were 10.5 and 10.3 times greater, respectively, among the seafaring workers than in the general population, while the risks of infections and genitourinary disorders were 10.2 and 9.7 times greater. Workers at high risk for health problems were typically more than 51 years old, with body weights of more than 75 kg, family histories of health problems, and heavy use of tobacco and alcohol. Compared with the general population of Valencia and the national population of Spain, the prevalences of ophthalmologic, digestive, respiratory, and circulatory disorders were higher in the seafaring workers.

Journal Article↗
PubMed1996

Conformity of Workers' and Occupational Health Physicians' Descriptions of Working Conditions.

To determine whether workers, describing their own work, and occupational physicians, describing typical workstations, would report the same working conditions, and whether the relationships between health status and working conditions described by these two sources would be similar. An epidemiologic survey was carried out in 1987-88 in 17 poultry slaughterhouses and six canneries in France. The data were collected in two ways: workers described their own working conditions, and occupational physicians described the working conditions at workstations in the same factories. The study included 507 workers who worked at fixed workstations that had been described by the 24 occupational physicians. Health data were obtained from the workers by the physicians during their annual visits. The agreement between workers and physicians in the descriptions of seven working conditions was analyzed. On the whole, the prevalences of exposures to the seven selected working conditions estimated by the two sources were similar. Nevertheless, the observed agreement was not necessarily high. When agreement existed about specific working conditions, the relationships observed between those conditions and workers' health were generally similar for the two sources. This result was stronger for physical health problems than for mental health problems. When both sources agreed that the worker was being exposed to a risk factor, the risk estimation was higher compared with the cases of discordant judgment. This study confirms the usefulness of information provided by experts but also the necessity to interview workers themselves about their working conditions.

Journal Article↗
PubMed2002

Epidemiologic evidence of cancer risk in textile industry workers: a review and update.

A meta-analysis of epidemiologic studies for textile industry workers was undertaken in an attempt to evaluate whether the cancer risk varies within the textile industry in relation to the job held or the textile fiber used. We combined studies published up until 1990, when an ad hoc IARC Monograph was issued, and those published after 1990 with the aim of appreciating evidence of reversing trends in cancer risk. Observed and expected cases reported in the original studies were summed up and the totals were divided to obtain a pooled relative risk (PRR) with a 95% confidence interval (CI) estimated with a fixed-effect model. We calculated a chi-square test (chi2) of heterogeneity among studies. When PRR and chi2 were both significant, PRR and CI were calculated with a random-effect model and the source of heterogeneity was investigated. Lung cancer risk was around 0.4 in the first study on cotton workers published in 1936, around 0.7 in subsequent studies, mostly published in the 1970s and 1980s, and around 1.0 in the last studies published in the 1990s. Papers published in the 1970s and 1980s produced consistent risk estimates for lung cancer risk, which was significantly lower than 1.0 in workers exposed to cotton (PRR = 0.77; CI = 0.69-0.86) and wool dust (0.71; 0.50-0.92), as well as in carders and fiber preparers (0.73; 0.54-0.91), weavers (0.71; 0.56-0.85), and spinners and weavers (0.78; 0.66-0.91). Lung cancer PRRs did not significantly deviate from 1.0 in textile workers using synthetic fibers or silk, and in dyers. Increased PRRs were found for sinonasal cancer in workers exposed to cotton dust, and in workers involved in spinning or weaving (4.14; 1.80-6.49). PRR was 1.46 (1.10-1.82) for cancer of the digestive system in textile workers using synthetic fibers or silk, and 1.34 (1.10-1.59) for colorectal cancer in spinners and weavers. The increased bladder cancer PRR in dyers (1.39; 1.07-1.71) is generally attributed to textile dye exposure. In studies published after 1990, there is a general tendency to move toward unity for all the cancer risk estimates, leading to an increasing heterogeneity among studies. Since adjustment for smoking made little difference to the findings, the latter could be attributed to the exposure to textile dusts. The recent findings could be due to a lowering of dust concentration in the workplaces. The reduction of cases of upper respiratory tract cancer parallels with a corresponding increase of lung cancer cases. So, preventive measures have paradoxically increased the lung cancer burden to the textile workers.

Adult↗
PubMed2004

An audit of biological monitoring of industrial lead workers by a UK laboratory over a 2-year period.

BACKGROUND: Medical surveillance of workers in the lead industry is under the statutory control of the Control of Lead at Work Act (CLAW). Over the years the CLAW regulations have been updated with a reduction in the suspension concentration for blood lead and the introduction of an action limit. As a result of these changes, an audit of blood lead measurement together with an evaluation of haemoglobin and zinc protoporphyrin (ZPP) measurements, also requested as part of surveillance, is required. METHODS: Results of measurements for blood lead, ZPP and haemoglobin in lead-exposed workers in 58 industries within the UK were collected over a 2-year period. RESULTS: For male workers, 8.8% of blood lead results [range 1-88 microg/dL (0.05-4.25 micromol/L), median 29 microg/dL (1.4 micromol/L), n = 3010] were above the action limit and 5.6% above the suspension limit set by CLAW. For female workers, 1.9% of blood lead results [range 1-74 micro g/dL (0.05-3.58 micromol/L), median 7 microg/dL (0.34 micromol/L), n = 161] were above the action limit. No significant correlation was found between blood lead and haemoglobin in the male workers (rs =-0.04, P = 0.024) and only a slight negative correlation for the female workers (rs =-0.25, P = 0.0016). ZPP showed an exponential relationship with blood lead in the male workers with a wide scatter of results. CONCLUSION: Haemoglobin and ZPP offer little towards the assessment of lead exposure in industrial workers. Blood lead in accordance with the CLAW regulations still offers the most appropriate means of industrial monitoring.

Chemical Industry↗
PubMed2000

Determinants of condom use in female sex workers in Surabaya, Indonesia.

In the developing world condom use among sex workers and their clients plays a dominant role in the transmission of HIV/STD. In Surabaya, Indonesia, data from the 1993 STD prevalence survey in female sex workers (brothels, street, massage parlours, barber shops, call-girl houses, and nightclubs) reveal that only 5% (33/692) of the brothel workers and 14% (25/177) of the street walkers had condoms in their possession at the time of the interview. During the last paid sexual intercourse, sex workers from the brothels, streets, and nightclubs used condoms infrequently (14%, 20%, and 25%, respectively). Sex workers from massage parlours, barber shops, and call girls were about 5 to 3 times more likely to use condoms than sex workers from nightclubs (adjusted odds ratio of 3.5, 4.9, and 4.2, respectively); thus condom promotion programmes should be targeted at sex workers at brothels, streets, and nightclubs. Programmes should include: (1) free distribution of condoms to sex establishments at the initial stage, and condom social marketing at later stages; (2) penalties, including legal sanctions, against any sex establishments that do not consistently use condoms; (3) participation of brothel owners and madams in encouraging sex workers to consistently have clients use condoms during sexual intercourse; and (4) establishment of sentinel surveillance to monitor STD/HIV and condom-use compliance.

Adolescent↗
PubMedDate not supplied

Off-day scheduling with hierarchical worker categories.

A work force includes workers of m types. The worker categories are ordered, with type-1 workers the most highly qualified, type-2 the next, and so on. If the need arises, a type-k worker is able to substitute for a worker of any type j greater than k (k = 1, ..., m - 1). For 7-day-a-week operation, daily requirements are for at least Dk workers of type-k or better, of which at least dk must be precisely type-k. Formulas are given to find the smallest number and most economical mix of workers, assuming that each worker must have 2 off-days per week and a given fraction of weekends off. Algorithms are presented which generate a feasible schedule, and provide work stretches between 2 and 5 days, and consecutive weekdays off when on duty for 2 weekends in a row, without additional staff.

Algorithms↗
PubMed1996

Leukemia mortality by cell type in petroleum workers with potential exposure to benzene.

Workers in the petroleum industry are potentially exposed to a variety of petrochemicals, including benzene or benzene-containing liquids. Although a large number of studies of petroleum workers have been conducted to examine leukemia and other cancer risks, few existing studies have investigated cell-type-specific leukemias. One of the major reasons for the lack of cell-type-specific analysis was the small number of deaths by cell type in individual studies. In the present investigation, all cohort studies of petroleum workers in the United States and the United Kingdom were combined into a single database for cell-type-specific leukemia analysis. The majority of these workers were petroleum refinery employees, but production, pipeline, and distribution workers in the petroleum industry were also included. The combined cohort consisted of more than 208,000 petroleum workers, who contributed more than 4.6 million person-years of observation. Based on a meta-analysis of the combined data, cell-type-specific leukemia risks were expressed in terms of standardized mortality ratios (meta-SMRs). The meta-SMR for acute myeloid leukemia was 0.96. The lack of an increase of acute myeloid leukemia was attributed to the low levels of benzene exposure in the petroleum industry, particularly in comparison to benzene exposure levels in some previous studies of workers in other industries, who had been found to experience an increased risk of acute myeloid leukemia. Similarly, no increase in chronic myeloid, acute lymphocytic, or chronic lymphocytic leukemias was found in petroleum workers (meta-SMRs of 0.89, 1.16, and 0.84, respectively). Stratified meta-analyses restricted to refinery studies or to studies with at least 15 years of follow-up yielded similar results. The findings of the present investigation are consistent with those from several recent case-control studies of cell-type-specific leukemia. Patterns and levels of benzene exposure in the petroleum industry are reviewed. The results of the present epidemiologic investigation are discussed in conjunction with recent advances in leukemogenesis from other scientific disciplines.

Benzene↗
PubMed1996

Evaluation of mortality and cancer incidence among alachlor manufacturing workers.

Alachlor is the active ingredient in a family of preemergence herbicides. We assessed mortality rates from 1968 to 1993 and cancer incidence rates from 1969 to 1993 for manufacturing workers with potential alachlor exposure. For workers judged to have high alachlor exposure, mortality from all causes combined was lower than expected [23 observed, standardized mortality ratio (SMR) = 0.7, 95% CI, 0.4-1.0], cancer mortality was similar to expected (6 observed, SMR = 0.7, 95% CI, 0.3-1.6), and there were no cancer deaths among workers with 5 or more years high exposure and 15 or more years since first exposure (2.3 expected, SMR = 0, 95% CI, 0-1.6). Cancer incidence for workers with high exposure potential was similar to the state rate [18 observed, standardized incidence ratio (SIR) = 1.2, 95% CI, 0.7-2.0], especially for workers exposed for 5 or more years and with at least 15 years since first exposure (4 observed, SIR = 1.0, 95% CI, 0.3-2.7). The most common cancer for these latter workers was colorectal cancer (2 observed, SIR 3.9, 95% CI, 0.5-14.2 among workers). Despite the limitations of this study with respect to small size and exposure estimating, the findings are useful for evaluating potential alachlor-related health risks because past manufacturing exposures greatly exceeded those characteristic of agricultural operations. These findings suggest no appreciable effect of alachlor exposure on worker mortality or cancer incidence rates during the study period.

Acetamides↗
PubMed1999

Immune responses in farm workers after exposure to Bacillus thuringiensis pesticides.

Although health risks to pesticides containing Bacillus thuringiensis (Bt) have been minimal, the potential allergenicity of these organisms has not been evaluated. Therefore, a health survey was conducted in farm workers before and after exposure to Bt pesticides. Farm workers who picked vegetables that required Bt pesticide spraying were evaluated before the initial spraying operation (n = 48) and 1 and 4 months after (n = 32 and 20, respectively). Two groups of low- (n = 44) and medium- (n = 34) exposure workers not directly exposed to Bt spraying were also assessed. The investigation included questionnaires, nasal/mouth lavages, ventilatory function assessment, and skin tests to indigenous aeroallergens and to a variety of Bt spore and vegetative preparations. To authenticate exposure to the organism present in the commercial preparation, isolates from lavage specimens were tested for Bt genes by DNA-DNA hybridization. Humoral immunoglobulin G (IgG) and immunoglobulin E (IgE) antibody responses to spore and vegetative Bt extracts were assayed. There was no evidence of occupationally related respiratory symptoms. Positive skin-prick tests to several spore extracts were seen chiefly in exposed workers. In particular, there was a significant (p < 0.05) increase in the number of positive skin tests to spore extracts 1 and 4 months after exposure to Bt spray. The number of positive skin test responses was also significantly higher in high (p < 0.05) than in low- or medium-exposure workers. The majority of nasal lavage cultures from exposed workers was positive for the commercial Bt organism, as demonstrated by specific molecular genetic probes. Specific IgE antibodies were present in more high-exposure workers (p < 0.05) than in the low and medium groups. Specific IgG antibodies occurred more in the high (p < 0.05) than in the low-exposure group. Specific IgG and IgE antibodies to vegetative organisms were present in all groups of workers. Exposure to Bt sprays may lead to allergic skin sensitization and induction of IgE and IgG antibodies, or both.

Antibodies, Bacterial↗
PubMed2002

Ethical activism: strategies for empowering medical social workers.

Little empirical research examines the extent medical social workers try to change attitudes, norms, expectations, and protocols to create a hospital environment that encourages their participation in ethical deliberations. The researchers developed an ethical activism scale that measured the extent medical social workers engaged in such ethical activism, confirming its reliability from data obtained from a sample of 162 medical social workers in 37 hospitals in the Los Angeles basin. They tested seven hypotheses that probed the extent specific ethics-training, organizational, and demographic variables influence the extent social workers engage in ethical activism. Data strongly suggest the need to expand ethics training to include tactics of ethical activism, since many social workers do not engage in ethical activism. Data also suggest the need to target such training to social workers in hospitals that are relatively unreceptive to social workers' participation in ethical deliberations, since social workers are least likely to engage in ethical activism in such settings.

Decision Making, Organizational↗
PubMed2002

Synergistic effects of dust and ammonia on the occupational health effects of poultry production workers.

OBJECTIVE: As production methods for livestock and poultry moved towards large industrial-scale confinement facilities, the occupational health community reported risks for respiratory illnesses in workers. Likely, greater risks for respiratory disease will occur with the continuing trend towards full-time confinement workers, who inspire a combination of bioaerosols, particulates, and gases. Although there have been numerous studies on the individual health effects of air contaminants inside confined animal production facilities, there have been no reports on the effects of combined exposures. The objective of this study was to investigate the combined health effects of air contaminants on poultry production workers. SAMPLE POPULATION: Two hundred and fifty-seven poultry production workers participated in this study. The workers represented various areas of the poultry industry, including turkey growing, broiler production, egg laying, and unloading/shakeling in poultry processing. Worker procedures pulmonary function testing was conducted before and after a four-hour work shift. The work environment was assessed for total and respirable dust, ammonia, endotoxin and CO2. The relationship of simultaneous total dust and ammonia exposures was examined by correlation, logistic modeling, and synergy index calculations. RESULTS: Synergy between ammonia levels and airborne dust explained up to 43% and 63% of the decline (respectively for Forced Expiratory Volume (FEV) in one second and Forced Expiratory Flow (FEF25-75) in pulmonary function over the work shift. Furthermore, assessing the synergy index indicated the combined effect of dust and ammonia is from 53 to 156% (greater combined than individually). The proportion of health effect due to synergy is 35%-61%. CONCLUSIONS: Synergy of simultaneous dust and ammonia exposures in a working environment raises the question of redefining exposure limits for organic dust and ammonia when workers are exposed simultaneously to these substances. CLINICAL RELEVANCE: Control of both dust and ammonia in livestock facilities is extremely important. Lack of control of both these contaminants will increase the risk of respiratory dysfunction to all exposed to this environment, including workers and veterinarians.

Journal Article↗