Pesticides and farmer health in Nicaragua: a willingness-to-pay approach to evaluation

A contingent valuation approach to assess the health effects of chemical pesticides among Nicaraguan vegetable farmers is presented. Farmers' valuation of health is measured as their willingness to pay (WTP) for low-toxicity pesticides. Results show that farmers are willing to spend an additional amount of about 28% of current pesticide expenditure for avoiding health risks. The validity of results is established in scope tests and with a two-step regression model. WTP depends on farmers' experience with poisoning, income variables, and current exposure to pesticides. The results can help in designing rural health policies and in the formulation of programmes aiming to reduce the negative effects of pesticides.

Cytogenetic biomonitoring of Brazilian workers exposed to pesticides: micronucleus analysis in buccal epithelial cells of soybean growers

Pesticides have been considered potential chemical mutagens and various agrochemical ingredients possess mutagenic properties. Biomonitoring provides a useful tool to estimate the genetic risk from exposure to a complex mixture of chemicals. In general genetic damage associated with pesticides occurs in human populations subject to high exposure levels due to intensive use, misuse or failure of control measures. Few studies have been carried out using the micronucleus (MN) analysis in buccal cells of farm workers and, from the available data, only one has found a positive relationship. Micronuclei were analyzed in 29 Brazilian workers exposed to pesticides in soybean fields and in 37 non-exposed individuals. The results obtained indicate that the mean number of cells with MN in the exposed group (3.55+/-2.13) was significantly higher than in the control group (1.78+/-1.23). The number of cells with MN was not influenced by age, smoking habit, smoking time, number of cigarettes/day, alcohol consumption and years of exposure to pesticides. The genotoxic potential of the pesticides used in soybean fields may explain the detectable increase of cells with MN in exposed workers.

Tobacco farming in rural Vietnam: questionable economic gain but evident health risks

BACKGROUND

In order to provide evidence on health impacts of the tobacco industry on cultivators in Vietnam, this study aims to provide comparison between tobacco cultivation related revenue and expenditure in selected areas in rural Vietnam and examine the relationship between tobacco cultivation and self-reported illness in the study population.

METHODS

Two tobacco farming communes and two non-tobacco farming communes were selected for this study. In each selected commune, 120 households were sampled using two-stage cluster sampling technique. Local health workers were recruited and trained to conduct household interviews using structured questionnaire.

RESULTS

Where the expenditure figures do not include personnel costs (as the farming work was almost always responsible by the family members themselves), it appeared that the average tobacco farmer did benefit financially from tobacco cultivation. However, if a personal opportunity cost was added to give a financial value to their labour, the profit from tobacco cultivation was seen to be minimal. The occurrences of 9 out of the 16 health problems were statistically significant higher among tobacco growing farmers compared to that among non-tobacco farmers. Tobacco farming was shown to be the second strong predictor of self-reported health problems among the farmer (after the effect of old age).

CONCLUSION

The present study provides evidence that can be used to increase public awareness about the harmful effects of tobacco growing.

Occupational exposure to organic dust, microorganisms, endotoxin and peptidoglycan among plants processing workers in Poland

The objective of present work was to determine and compare the components of bioaerosol in several sectors of plant processing industries. The study was conducted in 10 facilities engaged in herb and grain processing, flax threshing, grain storing, baking, and cereals production. The air samples were taken on glass fibre filters with an AS-50 sampler. We determined the concentrations of airborne microorganisms, dust, endotoxin and peptidoglycan. Total concentrations of viable airborne microorganisms ranged from 0.18-861.4 x 10(3) cfu/m(3). The highest levels of microbial contamination of the air were observed at flax farms, in grain elevators and in a herb processing plant. Gram-positive bacteria and fungi were detected at all sampling sites and their median concentrations were respectively 18.1 x 10(3) cfu/m(3) and 0.66 x 10(3) cfu/m(3). The concentration of Gram-negative bacteria ranged from 0.0-168.0 x 10(3) cfu/m(3). The concentration of thermophilic actinomycetes ranged from 0.0-1.45 x 10(3) cfu/m(3). Qualitatively, Gram-positive bacteria constituted 23-93% of the total microbial count. The most common species were: Staphylococcus spp., Curtobacterium pusillum, Rhodococcus fascians, Aureobacterium testaceum, Sanguibacter keddieii, Microbacterium spp., and Bacillus spp. Gram-negative bacteria formed 0-48% of the total count. The species Pantoea agglomerans dominated in all examined air samples. Fungi constituted 2.5-76.9% of the total microbial count. Among them, Penicillium spp., Mucor spp., Alternaria spp., Aspergillus niger, and Aspergillus spp. were found. The dust concentration ranged from 0.18-86.9 mg/m(3). The concentration of endotoxin was large and ranged from 0.0041-1562.6 microg/m(3). Muramic acid, the chemical marker of peptidoglycan, was detected in 9 out of 13 (69.2%) collected samples. The concentration of peptidoglycan ranged from 1.93-416 ng/m(3). A highly significant correlation was found between the individual components of bioaerosol determined in this study. The concentration of endotoxin was correlated with the concentration of Gram-negative bacteria, total microorganisms, and peptidoglycan (R>0.9, p<0.001). The concentration of peptidoglycan was correlated with the concentration of Gram-positive bacteria, Gram-negative bacteria, and total microorganisms (R>0.9, p<0.001).

Mental symptoms among Finnish farm entrepreneurs

The prevalence of mental symptoms among Finnish farm entrepreneurs in 2004 and 1994 was examined in two cross-sectional studies. The aim was also to examine associations between symptoms and background factors. Two random samples for computer-assisted telephone interviews comprised 1,182 full-time farmers in 2004 and 928 farmers in 1992. A binary logistic regression model was used to analyze the associations in the 2004 sample. Symptoms of weakness or fatigue and insomnia or difficulties in falling asleep were the most common symptoms in the 2004 survey, and both of these symptoms increased statistically significantly when comparing with the 1992 and 2004 surveys. Strenuousness of life and agricultural work had an association with mental symptoms. Forestry as a production sector and over two weeks of pesticide usage during the previous growing season also elevated the risk of mental symptoms. Moreover, illness or injury as well a lack of support from social relationships was associated with mental symptoms. One in four farm entrepreneurs had symptoms of weakness or fatigue in 2004. This result and the possible association between mental symptoms and pesticide usage needs special attention and further actions by health care services and other agricultural networks.

Intestinal parasitosis and use of untreated wastewater for agriculture in Settat, Morocco

An evaluation was made of the risk of contamination by faecal parasites in the population from the use of wastewater in agriculture. The study was based in 3 rural clusters in the northern region of Settat city, Morocco: 2 rural clusters exposed to untreated wastewater in agriculture and 1 not exposed. The sample comprised 333 people aged 3-60+ years: 214 exposed and 119 non-exposed. Stool samples were collected and examined for intestinal parasites. The results showed that the prevalence of intestinal parasitosis (i.e. evidence of at least 1 type of parasite) in the exposed group was significantly higher that the non-exposed group (66.4% versus 31.9%; relative risk 2.1). The household crowding index was also higher in the exposed group.

Ache, Pain, and Discomfort

The main purpose of the study was to investigate the prevalence of perceived symptoms of musculoskeletal disorders (MSD) among workers on large-scale dairy and pig farms in Sweden (herd size more than 300 cows and 450 sows) and to identify potential risk factors in the development of MSD. A study based on questionnaires was carried out among 42 workers on 10 large dairy farms and among 37 workers on 10 large pig farms in Southern Sweden during the autumn of 2002. Most importantly, the study showed that 86% of the dairy workers and 78% of the pig workers reported some kind of MSD during a period of 12 months prior to the study. The most frequently reported MSD among both the dairy and the pig workers were in the "upper extremities" (52% and 62%, respectively) especially in the shoulders and in "the back" (60% and 57%, respectively) especially in the lower back. Furthermore, being of short stature, doing repetitive work, working in awkward positions and being exposed to dust were significant risk factors in having MSD among the workers in this study. Thus, working with many cows and sows on large-scale farms in Sweden can be considered as a high risk job with regard to MSD.

Effect of manual feeding on the level of farmer's exposure to airborne contaminants in the confinement nursery pig house

The objective of the study is to demonstrate an effect of manual feeding on the level of farmer's exposure to airborne contaminants in the confinement nursery pig house. The levels of all the airborne contaminants besides respirable dust, total airborne fungi and ammonia were significantly higher in the treated nursery pig house with feeding than the control nursery pig house without feeding. Although there is no significant difference in respirable dust and total airborne fungi between the treatment and the control, their concentrations in the treated nursery pig house were also higher than the control nursery pig house. The result that the level of ammonia in the treated nursery pig house is lower than the control nursery pig house would be reasoned by the mechanism of ammonia generation in the pig house and adsorption property of ammonia to dust particles. In conclusion, manual feeding by farmer increased the exposure level of airborne contaminants compared to no feeding activity.

Green tobacco sickness and skin integrity among migrant Latino farmworkers

BACKGROUND

Green tobacco sickness (GTS) affects approximately one-quarter of tobacco workers. The primary aim of this analysis is to expand existing knowledge of GTS risk factors by delineating the association of measures of skin integrity with the prevalence of GTS among Latino farmworkers.

METHODS

Data are from a longitudinal study of skin disease among 304 North Carolina Latino farmworkers conducted in 2005.

RESULTS

18.4% of the farmworkers met the GTS case definition. Self-reported rash increased the odds of having GTS in the bivariate (OR 2.29, 95% CI 1.21, 4.35), and multivariate analyses (OR 3.30, CI 2.17, 5.02). Self-reported itch (OR 3.54, CI 2.38, 5.24) and superficial wounds (OR 2.49, CI 1.15, 5.39) had a significant relationship to GTS in the bivariate analysis.

CONCLUSIONS

These analyses extend current knowledge of GTS risk factors to include skin integrity. Farmworkers with rash and other skin conditions can protect these affected skin areas from exposure to the tobacco plant to reduce their risk of GTS.

Self report of skin problems among farmworkers in North Carolina

BACKGROUND

This study estimates the prevalence of self-reported skin problems among Latino farmworkers and identifies associated risk factors.

METHODS

The study used a longitudinal surveillance design. Participants were interviewed up to five times and reported skin problems and personal, work, and environment characteristics. Frequencies and counts were calculated for 13 skin problems. Adjusted odds ratios were obtained for six skin problems.

RESULTS

More than one-third of participants reported skin problems, including skin and nail fungus; sunburn; bumps, pimples, or acne; calluses; itching; rash; and insect bite. A variety of work and environment factors were associated with higher rates of skin problems. One of the strongest predictors was working in wet clothes or shoes.

CONCLUSIONS

Programs are needed to educate farmworkers about measures they can take to decrease their risk of skin problems. Changes in work practices and personal protective equipment provided could help decrease the prevalence of skin problems.

Enumerating outdoor aeromycota in suburban West Bengal, India, with reference to respiratory allergy and meteorological factors

Aeromycota may act as a reservoir of aeroallergens and upon inhalation may induce IgE-mediated Type I hypersensitivity reaction in pre-sensitized individuals. The total aerospora of an outdoor occupational setting (agricultural farm) in suburban West Bengal was sampled for two years (2002-2004) by a Burkard sampler. Concurrently, the cultivable aeromycota were trapped by an Andersen 2-stage sampler, cultured and tested for allergenic potential by skin prick test. The relationships between various climatic factors (temperature, relative humidity, rainfall and wind speed) and the distribution of aerospora were explored by Spearman correlation test. The antigenic extracts of 15 fungal species belonging to Alternaria, Aspergilli/Penicilli, Cladosporium, Curvularia, Drechslera, and Nigrospora evoked 10.8-54.8% skin reactivity in subjects with clinical history of respiratory allergy. The aerospora with skin sensitizing potential collectively represented a considerable fraction (52.3-58.4%) of the total aeromycota. The airborne concentration of Alternaria spores was higher than its borderline value of 100 spores m(-3) in May and June, whereas Cladosporium spore count exceeded its threshold limit value (3,000 spores m(-3)) in December, suggesting that this particular time of the year poses allergenic risk for individuals sensitive to these aerospora. Daily minimum temperature and rainfall appeared to be the most important meteorological factors to affect the concentration of aerospora in the study area.

Laryngeal cancer in farmers from Lublin region of Poland

The aim of the study was to analyse if work related risk factor had any influence on stage, localisation and histology of type of malignant tumour. Demographic and risk factors and results of treatment of farmers with patients working outside farming were compared. The group included 148 patients with primary laryngeal squamous cell carcinoma (LSCC) diagnosed and treated in our institution in the years 1999-2002. 84 (56.8%) of 148 patients were farmers and 64 (42.2%) patients worked outside farming. The univariate analysis of demographical and clinicopathological features of the farmers' group versus the other professions group with LSCC showed a statistical significance for sex, age and G stage. Nearly statistical significance was observed for the N stage (p=0.06) and for primary localisation of the tumour (p=0.05). The difference in 3 and 5-year survival rates between the group of farmers in comparison with the group of patients working outside farming and with LSCC was not significant for most of the demographical and clinicopathological features. Local, nodal or local plus nodal recurrence occurred in 15 (21.1%) of 84 farmers during 3 years follow-up. Distant metastases were observed in 7 (8.3%) of 84 farmers with LSCC, 6 to the lungs and one to the liver. Farmers with larynx cancer had different presentation pattern than other profession patients. The incidence of glottic cancer and well differentiated cancer was higher in farmers than in other professions. The prevalence of larynx cancer in women was significantly lower among farmers than in other professions. There were older patients in the group of farmers and relatively less women than in the group of patients with other professions.

Risk of occupational allergy to stored grain arthropods and false pest-risk perception in Czech grain stores

Arthropods are a documented cause of occupational allergy in cereal stores. Since the current allergenic risk of various arthropods in grain stores is not known, we evaluated its extent using data from the Czech Republic (CZ). We surveyed 514 grain storage units for pest composition and density. Recalculating literature data we established 4 density dependent classes of pooled mite "allergy-risk level" (ARL) in stored grain: (i) safe-ARL: 0 mites.g(-1) grain, (ii) low-ARL: up to 1 mite.g(-1) grain, (iii) high-ARL: from 1 to 5 mites.g(-1) grain, (iv) danger-acute asthma-ARL: higher than 5 mites.g(-1) grain. Farmers (15) were questioned for pest taxon-related pesticide treatments. Mites constituted the largest group of collected pests (92%) followed by psocids (5%), beetles (3%) and moths (0%). 60% of mites belonged to known allergen producing species; the most abundant were Acarus siro, A. faris, Tyrophagus putrescentiae and Lepidoglyphus destructor. Grain samples belonged to the established ARL classes as follows: (i) safe-ARL: 37% (ii) low-ARL: 53%; (iii) high-ARL: 6%; (iv) danger-acute asthma-ARL: 4%. The enquiry among farmers revealed that almost no pesticides were targeted solely to control mites. This study suggests that mites represent, due to their allergenic potential, density and frequency, the most serious source of allergens in stored grain in CZ. However, the medical aspect of pest control--such as allergy avoidance strategy--is overlooked since grain feeding insects were mostly chemically controlled, regardless of their relatively low density and allergen production in comparison with mites.

Allergenic pollens and spores in the working environment of Japanese pear farmers

Occupational allergies such as pollinosis are reported in several agricultural works in Japan. Many pollens and spores were observed in Japanese pear orchard during the artificial pollination season. By the study on daily symptoms in an allergic farmer, we confirmed that the pollinosis symptoms were most common and most severe during the artificial pollination. These results suggest that the exposure to allergenic pollens and spores induces allergic symptoms. Thus, caution should be paid for the avoidance of the exposure to these allergenic pollens and spores to prevent the allergy.

Airborne biological hazards in different pig fattening systems

In this research project two organic and two conventional housing systems for fattening pigs are assessed in regard to the emission of microorganisms, endotoxins and dust. The concentrations of microorganisms and endotoxins varied between the different housing systems while no distinct differences for the dust concentrations were observed. Endotoxins concentrations reached up to 14 495 EU/cubic meter median) in deep litter stable, indicating the high exposure with biological agents during farm work. The differences between the stables could not be assigned to the organic or conventional kind of husbandry but to the management of the systems.

[Farm work, dust exposure and respiratory symptoms among farmers]

OBJECTIVE

Environmental working conditions in rural areas, notably exposure to organic and mineral dusts, have been associated with increases in respiratory diseases. The objective of this study was to evaluate the prevalence of respiratory symptoms among farmers and the associations of these with occupational risk factors.

METHODS

This cross-sectional study was undertaken in 1996 with 1,379 farmers from Southern Brazil. Sociodemographic and farming-production parameters were collected, as were levels of exposure to organic and mineral dusts. Respiratory symptoms were assessed by a modified version of American Thoracic Society-Division of Lung Disease questionnaire. Multiple logistic regression analysis was used in analyses, controlling for confounding factors.

RESULTS

The majority (52%) of interviewees worked in activities with intense exposure to dust. Workers on farms with better economic indicators had a lower prevalence of respiratory symptoms. Poultry workers showed more symptoms of chronic respiratory disease (OR=1.60; 95% CI: 1.05-2.42). Farmers exposed to high concentrations of dust had more than 70% higher risk of asthma symptoms (OR=1.71; 95% CI: 1.10-2.67) and chronic respiratory disease symptoms (OR=1.77; 95% CI: 1.25-2.50).

CONCLUSIONS

The rural workers studied herein were exposed to high levels of organic and mineral dusts. Those exposed to higher dust concentrations, such as poultry workers, showed an increased risk of work-related respiratory symptoms. The implementation of respiratory protection programs is recommended, emphasizing workers involved with poultry production.

Effect of smoking and alcohol use during pregnancy on the occurrence of low birthweight in a farming region in South Africa

The aim of this case-control study was to determine the risk factors for low birthweight in a farming region in South Africa, with particular attention to maternal alcohol use and smoking, both independently and in combination. Data collection was via structured postpartum interviews and review of antenatal and delivery records. The study setting was a regional referral hospital in a farming region. The study subjects were 200 infants with birthweight < 2500 g (cases) and 200 unmatched control infants of normal weight born during the same period as the cases. The outcome measure was low birthweight, i.e. infant birthweight <2500 g. Results showed the contribution of term low birthweight (as a measure of intrauterine growth retardation) to the total low-birthweight incidence was almost 50%, indicating a substantial intrauterine growth retardation component in this population. Sociodemographic factors were not as predictive of low birthweight in this predominantly low income population. Smoking (adjusted OR 2.67, [95% CI 1.69, 4.20]) was the strongest life style-related predictor of low birthweight. The alcohol low-birthweight relationship was not significant when adjusted for smoking status (crude OR 2.15, [95% CI 1.37, 3.39]; adjusted OR 1.32, [95% CI 0.80, 2.20]). However, there appeared to be an interaction with combined use of these two substances during pregnancy that increased the risk of low birthweight (adjusted OR increased to 4.24, [95% CI 1.01, 17.76]. It is clear that life style factors such as smoking and drinking are contributing to the occurrence of low birthweight in the target region. A comprehensive health promotion programme needs to be implemented as an integral part of antenatal and family planning services, to reduce smoking and drinking by women in this community.

Sun exposure and non-Hodgkin lymphoma: a population-based, case-control study

To investigate the association between sun exposure and risk of non-Hodgkin lymphoma (NHL) by histologic subtypes and to explore whether or not vitamin D intake modify sun-NHL association, we analysed data from a population-based, case-control study conducted in Nebraska between 1999 and 2002. Information on sun exposure during the spring, summer, fall and winter was collected from 387 cases and 535 controls by telephone interview. We found no association between seasonal sun exposure and risk of NHL. Vitamin D intake was also not associated with NHL risk, nor does it modify the sun-NHL association. In contrast, total hours of sun exposure was inversely associated with the risk of NHL (odds ratio (OR)=0.7 comparing >30h/week to <14h/week, 95% confidence interval (CI)=0.5-1.1). Sun exposure was associated with a lower risk of NHL among farmers (OR=0.8, 0.5-1.3 for 14-30h/week; OR=0.6, 0.3-0.9 for >30h/week; p-trend=0.02), but not among non-farmers. Total hours of sun exposure was also inversely associated with risk of diffuse large B-cell lymphoma and T-cell lymphoma. In conclusion, our data suggest that total hours of sun exposure is associated with a lower risk of NHL, and the inverse association is not modified by vitamin D intake, is stronger among farmer, and may vary by subtypes.

Pesticide use and colorectal cancer risk in the Agricultural Health Study

We investigated the relationship between agricultural pesticides and colorectal cancer incidence in the Agricultural Health Study. A total of 56,813 pesticide applicators with no prior history of colorectal cancer were included in this analysis. Detailed pesticide exposure and other information were obtained from self-administered questionnaires completed at the time of enrollment (1993-1997). Cancer incidence was determined through population-based cancer registries from enrollment through December 31, 2002. A total of 305 incident colorectal cancers (212 colon, 93 rectum) were diagnosed during the study period, 1993-2002. Although most of the 50 pesticides studied were not associated with colorectal cancer risk, chlorpyrifos use showed significant exposure response trend (p for trend = 0.008) for rectal cancer, rising to a 2.7-fold (95% confidence interval: 1.2-6.4) increased risk in the highest exposure category. Aldicarb was associated with a significantly increased risk of colon cancer (p for trend = 0.001), based on a small number of exposed cases, with the highest exposure category resulting in a 4.1-fold increased risk (95% confidence interval: 1.3-12.8). In contrast, dichlorophenoxyacetic acid showed a significant inverse association with colon cancer but the association was not monotonic. Our findings should be interpreted cautiously since the literature suggesting that pesticides are related to colorectal cancer is limited. Nonetheless the possibility of an association between exposure to certain pesticides and incidence of colorectal cancer among pesticide applicators deserves further evaluation.

Contact dermatitis in tobacco farmworkers

Occupational skin disease is highly prevalent among agricultural workers. Tobacco cultivation and harvest are particularly hazardous for farmworkers. We report 5 migrant Latino farmworkers in North Carolina with contact dermatitis related to tobacco work. These cases show a characteristic distribution of contact dermatitis; the flexural and medial surfaces of the upper extremities were affected in each case, whereas most cases showed some involvement of the torso and axilla. This pattern most likely reflects a common occupational practice of holding the tobacco leaves under the arm and pressed against the body during harvesting.

[Lung diseases in farmers]

Respiratory diseases in farmers are complex and intricate diseases. Their diagnosis, management and treatment are difficult and their social and financial consequences can be painful. Respiratory diseases include: hypersensitivity pneumopathies, the most frequent and recognized one being farmer's lung disease; agricultural chronic bronchitis; allergic or non-allergic asthmas and rhinitis; and toxic bronchopneumopathies, of which organic dust toxic syndrome (or dust fever) is the most common, especially in animal breeding environments. The purpose of this article is to shortly describe these diseases, indicate their frequency and the main elements of their management: treatments and prevention methods.

Environmental exposure and health effects from concentrated animal feeding operations

Modern concentrated animal feeding operations generate sizeable amounts of manure and related emissions into water and air. These present potential harm to human health. Adverse respiratory effects have been documented among workers in these feeding operations, but there has been little research on wider environmental effects. Few conclusions are possible at this time but recent studies (including a report in this issue of Epidemiology by Radon and colleagues) suggest possible adverse effects. Respiratory outcomes of greatest concern include nasal allergies, airflow obstruction and asthma. Another concern among residents near concentrated animal feeding operations is adverse effects from malodors. The potential impact of these operations on quality of life and health needs to be documented.

Incidence of and risk factors for skin ailments among farmers working with wastewater-fed agriculture in Hanoi, Vietnam

The use of wastewater in agriculture and aquaculture is widespread in many developing countries, but limited information is available about the health hazards associated with this practice. To study the occurrence of skin ailments in relation to wastewater use in agriculture and aquaculture, an open cohort of 636 adults aged 15-70 years living in a wastewater-irrigated area in Hanoi, Vietnam, was followed by weekly visits for 12 months. A nested case-control study with 108 case/control pairs was conducted to investigate possible risk factors for skin ailments. The incidence rate of skin ailments was 32.5 episodes per 100 person-years at risk. Independent determinants of skin ailments included wastewater contact in the past 7 days (odds ratio (OR=2.74, 95% confidence interval (CI) 1.29-5.82), female gender (OR=2.48, 95% CI 1.06-5.76), fish farming-related jobs (OR=3.47, 95% CI 1.27-9.50) and lack of protective measures (OR=2.24, 95% CI 1.21-4.12). It is likely that effective promotion of personal protective measures and improved hygiene practices amongst wastewater users will mitigate the risk of dermatological problems and will thus be of benefit to public health in communities that rely on the use of wastewater for agricultural and aquacultural productions.

An occupational respiratory allergy caused by Sinapis alba pollen in olive farmers

BACKGROUND

Sinapis alba (white mustard) is a entomophilic species included in the Brassicaceae family. To date it has not been related to allergic sensitization or clinical respiratory disease.

METHODS

Twelve olive orchard workers had a history of rhinitis and/or bronchial asthma that occurred during control weed management and/or harvest, from January to March. They underwent skin prick tests (SPT) with S. alba pollen extract and a standard battery of aeroallergens. Sinapis alba pollen extract was prepared for performing quantitative skin tests, enzyme allergosorbent test and nasal challenge test (NCT). A portable monitoring station and an urban volumetric Hirst-type spore trap were used for the aerobiological study.

RESULTS

Eleven patients suffered from rhinitis and bronchial asthma and one had only from rhinitis. All patients were sensitized to S. alba pollen extract, and they showed a positive NCT response. In the urban aerobiologic monitoring station the amount of S. alba pollen only exceptionally reached peaks of 21 grains/m(3), whereas in the work environment peaks of 1801 grains/m(3) were detected between 15 February and 7 April.

CONCLUSIONS

We demonstrate the existence of a new occupational allergen for olive farmers: S. alba pollen. We point out the importance of perform aerobiological sampling within the occupational environment for the detection and quantification of the allergenic source.

The links between agriculture and health: an intersectoral opportunity to improve the health and livelihoods of the poor

Agriculture and health are linked in many ways. First, agriculture is essential for good health: it produces the world's food, fibre and materials for shelter; in many countries it is also an important source of livelihood among the poor. At the same time, agriculture can be linked with poor health, including malnutrition, malaria, foodborne illnesses, human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS), livestock-related diseases, chronic diseases and occupational ill-health. Health also affects agriculture: people's health status influences the demand for agricultural outputs, and in agricultural communities, poor health reduces work performance, reducing income and productivity and perpetuating a downward spiral into ill-health. This paper presents an overview of the bidirectional links between agriculture and health with a focus on the developing world. It develops a conceptual framework that brings together the various links between agriculture and health into a single broad framework. The framework comprises the core components of the agricultural supply chain (producers, systems and outputs), key health concerns and the mechanisms of common interaction between the agricultural and health components: income, labour, environment and access -- all key social determinants of health. These links between agriculture and health present an opportunity for the two sectors to work together to find solutions to each other's problems. Yet the health and agricultural sectors remain poorly coordinated. Leadership from global health and agricultural institutions is needed to build policies and good governance to facilitate integration, while capacity building is needed at all levels to help translate the conceptual links into comprehensive action on the ground. Health and agricultural researchers likewise need to work more closely together to achieve common goals.

Occupational exposure to organochlorine insecticides and cancer incidence in the Agricultural Health Study

Organochlorine (OC) insecticides have been regulated as possible human carcinogens primarily on the basis of animal studies. However, the epidemiologic evidence is inconsistent. We investigated the relationship between cancer incidence and OC insecticide use among pesticide applicators enrolled in the Agricultural Health Study, a prospective cohort study of 57,311 licensed applicators in Iowa and North Carolina enrolled between 1993 and 1997. Information on ever use of 7 OC insecticides (aldrin, chlordane, DDT, dieldrin, heptachlor, lindane, toxaphene) was collected from a self-administered questionnaire at enrollment. Lifetime exposure-days to OC insecticides were calculated using additional data from a take-home questionnaire completed by 25,291 participants (44% of total). We found no clear evidence of an association between use of OC insecticides and incident cancers (N = 1,150) ascertained through December, 2002. When we focused on individual insecticides and structurally similar groups (aldrin and dieldrin; chlordane and heptachlor), significantly increased relative risks of some cancers were observed for use of some chemicals (rectal cancer and chlordane, lung cancer and dieldrin, non-Hodgkin lymphoma (NHL) and lindane, melanoma and toxaphene, leukemia and chlordane/heptachlor). Some significant decreased relative risks were also observed (colon cancer and aldrin; overall cancer and heptachlor). In conclusion, we did not observe any clear relationship between cancer risk and the use of OC insecticides. Our chemical-specific findings are based on small numbers and multiple comparisons, and should be interpreted with caution; however, some observed associations (lindane and NHL, chlordane/heptachlor and leukemia) are supported by previous evidence.

Treating skin disease: self-management behaviors of Latino farmworkers

Latino migrant and seasonal farmworkers experience high rates of skin disease that result from their working and living conditions. Knowledge of the ways farmworkers treat skin disease symptoms will provide a foundation for developing culturally appropriate health education, improving the delivery of health services, and improving occupational health policy for agricultural workers. The purpose of this paper is to describe skin disease self-management practices among Latino migrant and seasonal farmworkers in North Carolina. This analysis uses a qualitative design based on in-depth interviews with 30 Latino farmworkers (six females, 24 males). Computer assisted, systematic procedures are used to analyze the verbatim transcripts of these interviews. Participants shared a consistent set of health self-management actions in treating skin disease. These actions were within the domains of self-care and medical care. A model of skin disease self-management among Latino farmworkers includes the self-care actions of hygiene, use of home remedies and use of over-the-counter remedies, with farmworkers often combining different domains of self-care. While farmworkers acknowledge the benefits of medical care, they are also mindful of barriers to its use, including cost, transportation and language. The large percentage of farmworkers who experience skin problems indicates that health outreach workers who serve this population need to provide education on preventing and treating skin problems, and they need to recommend to farmworkers appropriate over-the-counter medicines for the treatment of these skin problems. Appropriate medical care for treating skin problems that are dangerous and reduce farmworkers' quality-of-life needs to be made available to this population.

Disabling work-related persistent photosensitivity following photoallergic contact dermatitis from chlorpromazine and olaquindox in a pig breeder

The use of veterinary medicines and medicated feed has a potential for the exposure of agricultural workers to pharmaceuticals with phototoxic and photoallergic side-effects. We present a 67-year-old self-employed farmer and pig breeder with a 22-year history of severe persistent photosensitivity following photoallergic contact dermatitis due to direct occupational dermal and airborne contact to chlorpromazine (sedative) and olaquindox (antibiotic and animal growth promoter, AGP). His first dermatitis symptoms appeared at the age of 45 when the pig breeding was intensified. He showed erythematous, scaly, and pruritic plaques localized symmetrically on the sun-exposed backs of his hands, fingers, and forearms, spreading to his face and other sun-exposed body sites. Without protective measures, he injected the animals with chlorpromazine. Besides, for several years he mixed by hand a powder containing olaquindox into the pigs' dry food. Epicutaneous and photo-patch tests showed positive reactions to promethazine, chlorpromazine, and olaquindox. In spite of the complete avoidance of the identified photoallergens for several years, his life is still extremely disabled due to the persistent photosensitivity. Our case report stresses the observation that olaquindox and chlorpromazine as phototoxic agents and photoallergens are capable of inducing a persistent and severe photosensitivity for many years, even after termination of exposure. Although the use of phenothiazine derivates and APGs for animals has meanwhile been banned in the European Union (EU), AGPs are still widely used in Asia. Physicians, especially occupational physicians, should be still aware of these phototoxic and photoallergic agents to reduce the burden of skin disease at work.

Host Factors, Occupation, and Testicular Cancer in Saskatchewan, Canada: 1979-2002

The incidence rates of testicular cancer are increasing in several countries, especially among younger adults. The role of agricultural exposure in the etiology of testicular cancer is contentious. We extracted information related to the host, lifestyle, and tumor characteristics from the files of the Saskatchewan Cancer Agency for all cases (n = 517) of testicular cancer diagnosed in Saskatchewan between 1979 and 2000. The following questions were the subject of this initial inquiry: (1) Are tumor characteristics similar or different among occupational groups dichotomized into farmer/nonfarmer? (2) Are host characteristics similar or different among occupational groups? (3) Is farming as an occupation one of the independent predictors of tumor stage at diagnosis? Statistical analyses were restricted on 486 cases. The nonfarmers (n = 349) had smaller tumors in length on average, and more of them were diagnosed at stage I compared to farmers (n = 72). Occupation was not recorded for 65 cases. Farmers were older than nonfarmers. In logistic regression analyses with adjustment for relevant variables as cited in the literature, individuals with nonseminomas [OR (95% CI) 1.99 (1.30-3.31)] and < or = 26 years old at diagnosis [2.12 (1.15-3.93)] were significantly more likely to be diagnosed with a stage 2 or higher tumor. Farmers were significantly more likely than nonfarmers to be diagnosed at stage 2 or higher [1.76 (1.00-3.10)]. Based on our data, the significant predictors of being diagnosed with stage 2 and higher are: presence of nonseminoma, < or = 26 years old, and farming as an occupation.

Preliminary recognition of whole body vibration risk in private farmers' working environment

The objective of the study was the preliminary recognition of whole body mechanical vibration risk among farmers in the rural work environment. The study covered 15 farms using cultivated land of the size of over 10 ha, carrying out mixed production (plant-animal), equipped with agricultural tractors, and a basic set of tractor-mounted agricultural machinery, with a partial contribution of self-propelled agricultural machines. The scope of the study covered the measurements of effective vibration RMS acceleration (equivalent, maximum, minimum, peak) frequency corrected on the seats of agricultural vehicles in the three spatial directions of vibration (X, Y, Z). These measurements were realized while performing various field and transport work activities during the period of the whole year. A analysis of the peak, maximum and minimum vibration accelerations confirms that in the agricultural occupational environment there occurs a considerable variation of the vibration values registered. This is also evidenced by high values of the Crest Factor, sometimes exceeding a score of 10. Analysis of the registered equivalent values of vibration acceleration (frequency corrected) from the hygienic aspect showed that vibration occurring on the seats may create risk for farmers' health while performing such work activities as: tending and raking of hay, fertilizers spreading, soil aggregation, grass mowing and cultivation. Analysis of the spatial distribution of the measured, frequency corrected vibration accelerations indicates that considerably the highest acceleration values occur in the vertical plane (direction-Z). Literature data clearly confirm an unfavourable effect of whole body vibration present in agricultural vehicles on discomfort and the occurrence of back pain in the operators, especially in the low back region (lumbar spine), as well as degenerative changes in the spine.

Levels of fungi and mycotoxins in the samples of grain and grain dust collected from five various cereal crops in eastern Poland

During combine harvesting of 5 various cereal crops (rye, barley, oats, buckwheat, corn) 24 samples of grain and 24 samples of settled grain dust were collected on farms located in the Lublin province of eastern Poland. The samples were examined for the concentration of total microfungi, Fusarium species, deoxynivalenol (DON), nivalenol (NIV), and ochratoxin A (OTA). Microfungi able to grow on malt agar were present in 79.2% of grain samples and in 91.7% of grain dust samples in the concentrations of 1.0-801.3x10(3) cfu/g and 1.5-12440.0x10(3) cfu/g, respectively. The concentration of microfungi in grain dust samples was significantly greater than in grain samples (p<0.01). Fusarium strains were isolated from 54.2% of grain samples and from 58.3% of grain dust samples in the concentrations of 0.1-375.0x10(3) cfu/g and 4.0-7,700.0x10(3) cfu/g, respectively. They were found in all samples of grain and grain dust from rye, barley and corn, but only in 0-16.7% of samples of grain and grain dust from oats and buckwheat. DON was found in 79.2% of grain samples and in 100% of grain dust samples in the concentrations of 0.001-0.18 microg/g and 0.006-0.283 microg/g, respectively. NIV was detected in 62.5% of grain samples and in 94.4% of grain dust samples in the concentrations of 0.004-0.502 microg/g and 0.005-0.339 microg/g, respectively. OTA was detected in 58.3% of grain samples and in 91.7% of grain dust samples in the concentrations of 0.00039- 0.00195 microg/g and 0.00036-0.00285 microg/g, respectively. The concentrations of DON, total fusariotoxins (DON+NIV) and OTA were significantly greater in grain dust samples than in grain samples (p<0.05, p<0.05, and p<0.001, respectively). The concentration of Fusarium poae in the samples of rye grain and dust was significantly correlated with the concentrations of DON (p<0.05), NIV (p<0.01), and total fusariotoxins (p<0.05). Similarly, the concentration of Fusarium culmorum in the samples of barley grain and dust was significantly correlated with the concentration of total fusariotoxins (p<0.05). A significant correlation was also found between the concentration of total fungi grown on malt agar and the concentration of OTA (p<0.05). In conclusion, although the concentration of DON, NIV and OTA in the samples of grain dust collected from 5 various cereals on farms in eastern Poland was not large, the persistent presence of these mycotoxins in over 90% of examined samples poses a potential health risk of chronic respiratory intoxication for exposed grain farmers.

Toxicity Study of the Volatile Constituents of Myoga Utilizing Acute Dermal Irritation Assays and the Guinea‐Pig Maximization Test

Myoga is a fragrant plant which is the special product of Japan and is cultivated throughout Japan. According to our earlier investigation (unpublished data) of myoga cultivators in Japan, 8 of 35 cultivators experienced contact dermatitis in the harvest season. The purpose of this study was to assess the allergenicity of myoga and its major volatile components. The volatile components of myoga were analyzed by gas chromatograph (GC). They included a-pinene, beta-pinene and R-(+)-limonene. We performed a toxicity study of each of the major fragrant components of myoga using acute dermal irritation assays and the Guinea-Pig Maximization test (GPMT) in order to probe the mechanism of allergic contact dermatitis. In acute dermal irritation assays, alpha-pinene, beta-pinene and limonene showed positive responses at concentrations of 4%; limonene oxide at 20% and myoga showed a positive response at concentrations of 100%. From the results of the GPMT, according to Kligman scores, limonene oxide was identified as an extreme skin sensitizer and myoga as a mild skin sensitizer. The results of the present study show that R-(+)-limonene is the most important allergen amongst the chemical components of myoga, and we consider it to be the reason why myoga cultivators experience allergic contact dermatitis.

Use of pesticides and its impact on health of farmers in South India

The relationship between extent of pesticide use and signs and symptoms of illnesses due to exposure was assessed in a cross-sectional survey of 631 farmers (537 men and 94 women) in South India. Responses to questionnaires showed that 433 farmers (68.6%) sprayed pesticides themselves and were thus directly exposed. More than 75% used moderately or highly hazardous pesticides; 88% used no protection while handling pesticides. About 50% of sprayers mixed different brands. Retailers were the source of information about pesticides for 56%. The farmers reported excessive sweating (36.5%), burning/stinging/itching of eyes (35.7%), dry/sore throat (25.5%), and excessive salivation (14.1%), all more prevalent among sprayers. Among men, excessive sweating and eye and throat problems were significantly associated with exposure. There is a need to raise farmers' and authorities' awareness of the need to use protective gear when handling pesticides.

Occupational titles as risk factors for Parkinson's disease

BACKGROUND

Job title or employment sector may be associated with Parkinson's disease (PD).

METHODS

In a case-control study, in four European centres, lifetime occupational histories were coded using modified International Standard Industrial Classification (ISIC) and Dictionary of Occupational Titles (DOT). We employed multiple logistic regression analyses adjusting for age, gender, smoking and family history of PD.

RESULTS

A total of 649 cases and 1587 controls were recruited. Scottish data showed a non-significant increased risk for agriculture (DOT: OR 1.32, 95% CI 0.81-2.16; ISIC: OR 1.30, 95% CI 0.84-2.02) and reduced risk for 'transport and communication' (ISIC: OR 0.60, 95% CI 0.37-0.97). Subsequent four-centre analyses showed reduced risk for processing occupations (DOT: OR 0.69, 95% CI 0.5-0.95). An association with pesticide exposure, found using detailed exposure assessment, was not apparent using job classification.

CONCLUSIONS

In contrast to retrospective exposure assessment, job or industrial sector is a weak indicator of toxic exposures such that true associations may be missed.

Estimates of acute pesticide poisoning in agricultural workers in less developed countries

The benefits of crop protection products have to be balanced against the risks to farmers and other agricultural workers handling and applying them. The extent of acute pesticide poisoning in these workers, particularly in less developed countries, has often been based on inadequate information. A number of approaches have been taken by researchers to acquire information on pesticide poisoning. These have resulted in worldwide (global) estimates and regional, localised or field assessments. The methods include descriptive epidemiology, cross-sectional and case studies. Attempts to estimate global pesticide poisonings have often been based upon extrapolations and assumptions from chemical-related fatalities in a small number of countries; such estimates do not provide reliable data. Epidemiological studies, relying mainly on hospital and poison centre data, have been biased towards the more severe poisonings, whereas field studies indicate that occupational pesticide poisoning is associated with less severe and minor effects. Many reports do not adequately distinguish between intentional, accidental and occupational pesticide poisoning statistics or are dominated by cases of intentional (suicidal) poisoning which, by their nature, result in severe or fatal results. The majority of reports do not adequately describe whether individual cases are minor, moderate or severe poisonings. In order to assess information on acute pesticide poisoning in agricultural workers in less developed countries and to draw conclusions on the extent and severity of occupational poisoning, the most recent (post-1990) literature was reviewed. Data were also derived from the World Health Organization (WHO), United Nations Environment Programme (UNEP) and the International Labour Office (ILO). The collected information was analysed to assess the extent and severity of occupational acute pesticide poisoning in less developed countries. Occupational acute pesticide poisonings in these countries are a small proportion of overall reported poisoning and are associated with the more minor effects of pesticides. They are a small proportion (<1-4%) of the several million cases of occupational injuries and ill health in agricultural workers worldwide. However, improvements are required for the collection of acute pesticide poisoning data in less developed countries and in the verification of the circumstances of poisonings and their relative severity. There is the need to move away from further attempts to estimate global data and concentrate instead on obtaining reliable data from realistic crop protection activities.

Hay fever and asthma symptoms in conventional and organic farmers in The Netherlands

BACKGROUND

Farming has been associated with respiratory symptoms and with protection against atopy. To date, effects of organic farming on respiratory health have not been studied.

AIMS

To (1) compare hay fever and asthma-like symptoms in organic and conventional farmers and (2) assess associations between current and childhood farm exposures and respiratory health effects by conducting a survey.

METHODS

Questionnaire data from 1205 conventional and 593 organic farmers were evaluated. Associations between health effects and farm exposures were assessed by logistic regression analyses.

RESULTS

Organic farmers reported less wheezing with shortness of breath and slightly more hay fever than conventional farmers. However, organic farming was not an independent determinant of hay fever when adjusted for farming practices and potential confounders. Livestock farmers who grew up on a farm had a threefold lower prevalence of hay fever than crop farmers without a farm childhood (odds ratio (OR) 0.3, 95% confidence interval (CI) 0.1 to 0.5). Both crop farmers who grew up on a farm and livestock farmers who did not grow up on a farm had a reduced prevalence, although less pronounced and not statistically significant. Use of disinfectants containing quaternary ammonium compounds was positively related to hay fever (OR 2.1, 95% CI 1 to 4.4). No effects of farming practices were found for asthma.

CONCLUSIONS

Our study adds to the evidence that a farm childhood in combination with current livestock farming protects against allergic disorders. This effect was found for both organic and conventional farmers.

Causes of acute, undifferentiated, febrile illness in rural Thailand: results of a prospective observational study

The adult patients who, between July 2001 and June 2002, presented at any of five hospitals in Thailand with acute febrile illness in the absence of an obvious focus of infection were prospectively investigated. Blood samples were taken from all of the patients and checked for aerobic bacteria and leptospires by culture. In addition, at least two samples of serum were collected at different times (on admission and 2-4 weeks post-discharge) from each patient and tested, in serological tests, for evidence of leptospirosis, rickettsioses, dengue and influenza. The 845 patients investigated, of whom 661 were male, had a median age of 38 years and a median duration of fever, on presentation, of 3.5 days. Most (76.5%) were agricultural workers and most (68.3%) had the cause of their fever identified, as leptospirosis (36.9%), scrub typhus (19.9%), dengue infection or influenza (10.7%), murine typhus (2.8%), Rickettsia helvetica infection (1.3%), Q fever (1%), or other bacterial infection (1.2%). The serological results indicated that 103 (12.2%) and nine (1%) of the patients may have had double and triple infections, respectively. Leptospirosis and rickettsioses, especially scrub typhus, were thus found to be major causes of acute, undifferentiated fever in Thai agricultural workers.

Latino farmworker perceptions of the risk factors for occupational skin disease

BACKGROUND

Farmworkers in the US constitute a medically underserved population at substantial risk for numerous environmental and occupational health problems. Most US farmworkers are Latino. Skin disease is one health problem to which farmworkers are particularly vulnerable. Interventions to reduce skin disease must be adapted to farmworkers' understanding of such disease, including their beliefs or knowledge of risk factors for skin disease.

METHODS

Structured by the Explanatory Models of Illness framework, this analysis uses a qualitative design based on in-depth interviews with 30 Latino farmworkers (6 females, 24 males) to determine beliefs and perceptions of the causes of common occupational skin diseases in this population. Computer assisted, systematic procedures are used to analyze the verbatim transcripts of these interviews.

RESULTS

Skin disease is a major concern among farmworkers because it affects work, social interaction, and other aspects of their lives. Farmworker beliefs and perceptions of skin disease causation can be integrated into a general model in which perceived risk factors include sun and heat, chemicals, plants, insects, moisture, hygiene, and contagion. Each of these factors is moderated by the individual's personal susceptibility to that cause. The interaction or combination of two or more factors is thought to amplify their individual effects.

CONCLUSIONS

The farmworker model of skin disease causation suggests important content for health education to reduce skin disease among farmworkers.

Consequences of vector behavior in epidemiology of onchocerciasis on the Firestone Rubber Plantation in Liberia

In the current study, we have assessed the distribution of black fly vectors and the occurrence of onchocerciasis among residents of the Firestone Rubber Plantation (FRP) in Liberia. The degree of endemicity of onchocerciasis on the FRP is correlated with the breeding of Simulium yahense on the Du River and Simulium soubrense on the Farmington River, as well as with the feeding behavior of these black fly vectors. S. yahense is highly anthropophilic and highly susceptible to Onchocerca volvulus, thus, it is apparently the primary vector of O. volvulus on the plantation. S. soubrense is predominantly zoophilic; consequently, it has a low capacity for transmitting of O. volvulus to humans. The prevalence of the disease is hyperendemic in the divisional camps near the Du River, affecting 77.6% to 94.4% of males and 64.9% to 88.9% of females. In the camps along the Farmington River, the disease is hypoendemic, affecting 26.1% to 49.2% of males and 25.6% to 35.1% of females. The mean intensity of infection in the camps near the Du River was 14.1 microfilariae (mf)/mg of skin in males and 13.7 mf/mg of skin in females. The density of microfilariae in people in the camps along the Farmington River was 4.8 mf/mg of skin in males and 1.9 mf/mg of skin in females. The age-specific infection in camps along both rivers substantially increased after the ages 21-30, reaching a maximum at ages 41-50. The mean density of mf/mg of skin in three anatomic locations (calf, hip, and shoulder) was 28.0, 24.5, and 14.1 mf/mg of skin, respectively, for those living on the Du River, and 10.2, 7.6, and 5.8 mf/mg of skin, respectively, for those on the Farmington River.

Dust and noise exposures among farmers in Southland,New Zealand

This was a cross-sectional survey of the health of farmers in Southland, New Zealand and in a sub-sample, included daily noise and inhalable dust exposure measurements, and a walk through assessment of farm buildings. The median inhalable dust level for arable farmers was 1.7 mg/m(3) with 0.7 mg/m(3) for sheep farmers (NZ standard 10 mg/m(3)). Total daily noise exposure levels were 86.8 dB(A) for sheep farmers, and 85.7 dB(A) for mixed farmers (NZ standard 85 dB[A]). A higher proportion of farmers had low ratings for chemical safety and dust levels in farm buildings compared with other parameters, such as stockhandling or machinery safety. Noise remains an important hazard for NZ farmers, although dust less so, based on inhalable levels. Reducing noise at source is required, as well as greater use of hearing protection. Inhalable dust levels were low due to the nature of farming in NZ where outdoor pastoral farming is the norm.

Occupational respiratory allergy to cyclamen pollen: a case report

A case of cyclamen (Cyclamen persicum) pollen allergy is described on a flower cultivator. The diagnosis was assessed by skin test, methacoline test, nasal provocation test and RAST. SDS-PAGE and immunoblotting have shown an intense response against a 18 kDa component and a weaker one at 100 Kda. A RAST inhibition against Cupressus sempervirens and Acacia floribundia showed no identity with cyclamen. This case confirm the cyclamen allergenity, in professional exposure. The nasal challenge prove to be very useful to confirm allergic sensitizations an we emphasize the necessity of preventive measures of protection for those florists who cultivate cyclamen plants.

Seroprevalence of leptospirosis among high-risk population of Andaman Islands, India

Leptospirosis is a severe spirochetal zoonosis in the world. It is considered an occupational disease of persons engaged in agriculture, sewage works, forestry, and animal slaughtering. A study was conducted with an objective of assessing the seroprevalence of leptospirosis among the high-risk groups of Andaman Islands. A total of 611 sera samples from different high-risk populations were collected and tested by microscopic agglutination test (MAT). Genetic characterization of the isolate was done by randomly amplified polymorphic DNA (RAPD) fingerprinting, and serological characterization was done using monoclonal antibody technique. Antibodies to leptospires were detected in 322 samples giving an overall seroprevalence of 52.7%. The seroprevalence was highest among agriculture workers (62.5%) followed by sewage workers (39.4%), animal handlers (37.5%), forest workers (27.3%), and butchers (30.0%). Seroprevalence among control population was 14.7%, which was comparatively less than that of the high-risk population groups. Subject sera were most commonly reacted with organisms of the serogroup Grippotyphosa followed by Australis, and the pattern was similar in control group. Four leptospires were isolated from agriculture workers who were admitted to the public health center (PHC) with complaints of fever and body ache. Human isolates were compared with two rodent (Rattus norvegicus) isolates from the same area of agriculture workers to get initial information about the transmission cycle of leptospirosis in the study community. Randomly amplified polymorphic DNA fingerprinting pattern of the strains recovered from the rodents and human patients were identified as belonged to genomo-species Leptospira interrogans. The antigenic characterization of the strains recovered from them belonged to serovar Valbuzzi of serogroup Grippotyphosa. The study showed that people engaged in high-risk activities such as agriculture, sewage cleaning, animal handling, animal slaughtering, and forestry are frequently exposed to leptospirosis, and hence control strategies targeting these populations could be more effective.

Eye and respiratory symptoms in poultry processing workers exposed to chlorine by-products

BACKGROUND

CDC/NIOSH responded to a request to investigate complaints of eye and respiratory irritation among workers in a poultry processing facility's evisceration department.

METHODS

Investigators administered symptom questionnaires and sampled for chlorine and chloramines. Spirometry was performed on workers before and after their work shift.

RESULTS

Symptoms were significantly more prevalent in evisceration workers than in dark meat workers (a control group). Air concentrations of chloramine compounds (i.e., trichloramine and 'soluble chlorine') were significantly higher in the evisceration area than the dark meat area. Exposure levels were significantly higher for employees reporting various symptoms compared to employees not reporting those symptoms. Mean trichloramine exposure concentrations were significantly higher in workers with significant cross-shift declines in lung function; air concentrations of 'soluble chlorine' were higher as well, however, not significantly so.

CONCLUSIONS

Results of this evaluation suggest a health hazard may exist from exposure to chloramines.

Agricultural seed dust as a potential cause of organic dust toxic syndrome

AIMS

Episodes of serious work related health problems resembling organic dust toxic syndrome (ODTS) in workers of a grass seed quality inspection laboratory prompted the authors to study personal endotoxin exposure levels in this facility and in the agricultural seed processing industry. In addition, microbial and inflammatory characteristics of agricultural seeds were studied.

METHODS

The authors assessed inhalable dust and endotoxin levels in 101 samples from 57 workers in grass, cereal, and vegetable seed plants who were handling mainly grass seeds as bulk product, and horticulture seeds in smaller quantities. Additionally, real-time dust exposure was measured using a DataRAM monitor in 12 grass seed workers to obtain more information on exposure patterns during specific tasks. Endotoxin concentrations in seed extracts were determined by LAL assay and seed samples were analysed by scanning electron microscopy. Release of inflammatory cytokines was measured in supernatants of whole blood samples stimulated with lipopolysaccharide (LPS) or agricultural seed extracts in a human whole blood assay (WBA).

RESULTS

Endotoxin concentrations in personal samples were high (geometric mean 1800 EU/m3), particularly in the grass seed quality inspection lab where endotoxin levels up to 274 000 EU/m3 were measured. The recommended health based endotoxin exposure limit of 50 EU/m3 was amply exceeded in almost all personal samples. Job tasks dumping and mixing were associated with highest dust and endotoxin exposures, which was confirmed by real-time measurements. Microbial infestation was found in almost all seed samples. WBA results showed that most seed extracts were capable of inducing a pronounced dose dependent cytokine release.

CONCLUSIONS

Workers handling grass, cereal, or vegetable seeds are at risk of exposure to high levels of endotoxin containing seed dust. Occupational exposure to inhalable agricultural seed dust can induce inflammatory responses, and is a potential cause of ODTS.

The Upper Midwest Health Study: A Case-Control Study of Primary Intracranial Gliomas in Farm and Rural Residents

Since several studies indicated that farmers and agricultural workers had an excess risk of brain cancer, the National Institute for Occupational Safety and Health initiated the Upper Midwest Health Study to examine risk of intracranial glioma in the non-metropolitan population. This population-based, case-control study evaluated associations between gliomas and rural and farm exposures among adults (ages 18 to 80) in four upper midwestern states (Iowa, Michigan, Minnesota, Wisconsin). At diagnosis/selection, participants lived in non-metropolitan counties where the largest population center had fewer than 250,000 residents. Cases were diagnosed 1 January 1995 through 31 January 1997. Over 90% of 873 eligible ascertained cases and over 70% of 1670 eligible controls consented to participate. Participants and nonparticipants, evaluated for "critical questions" on main and refusant questionnaires, differed significantly in farming and occupational experience, ethnicity, education, and lifestyle. The 1,175 controls were more likely than the 798 cases to have reported ever drinking alcohol (77% vs. 73%, adjusted odds ratio (OR) 0. 73, 95% confidence interval (CI) 0.59-0.92) and having had panoramic dental x-rays (34% vs. 29%, OR 0. 75, CI 0.61-0.92). Controls spent a greater percentage of their lives in non-metropolitan counties (78% vs. 75%, OR 0.81, CI 0.67-1.09). Among ever-farmers, controls were more likely to have had exposure to farm insecticides (57% vs. 50%, OR 0.75, CI 0.59-0.95) and farm animals (96% vs. 91%, OR 0.48, CI 0.25-0.90). Moving to a farm as an adolescent (ages 11 to 20) vs. as an adult was associated with a greater risk of glioma. In our study sample, farm or rural residence and summary farm exposures were associated with decreased glioma risk. However, nonparticipation by never-farming eligible controls could have affected results. Comparisons of farm chemical exposures may clarify associations between farming and glioma that others have reported.

Health and social impacts of tobacco production

OBJECTIVES

To summarize current knowledge about the health and social consequences of tobacco production and to outline research needed to better understand these effects.

DATA SOURCES

The literature documenting the effects of tobacco production is scattered, and not always published in peer-reviewed sources. We undertook a systematic search using (1) a literature file based on over a decade of research on the health effects of tobacco work, (2) searches of computerized data bases (Medline, Science Citation Index, Agricola), (3) a review of new sources cited in literature uncovered through data base searches, and (4) professional contacts with others working on the effects of tobacco production.

DATA SYNTHESIS

The health effects of tobacco production include nicotine poisoning (green tobacco sickness), pesticide exposure, respiratory effects, musculoskeletal and other injuries. Most research has focused on nicotine poisoning. Social effects of tobacco production include social disruption for communities in which tobacco production is declining (unemployment, economic loss), and for communities in which tobacco production is being introduced (loss of local food production and local autonomy).

CONCLUSIONS

Research is needed on the effects of tobacco work on the health of women and children through exposure to nicotine and pesticides, the effects of chronic nicotine exposure on all tobacco workers, the neurotoxic effects of pesticide exposure and its relationship with mental health, and the effects of growing tobacco on using tobacco. Greater effort is needed to document the social disruption in communities that are economically dependent on tobacco production, particularly those in developing countries.

Characteristics of annual exposure to noise among private farmers on family farms of mixed-production profile

The objective of the study was the recognition and evaluation of annual exposure to noise among private farmers on farms engaged in mixed (plant-animal) production. The study covered 16 family farms using land of the size 13-30 ha (20.4 ha on average). The farms were equipped with agricultural tractors (2.4 tractors on average), selected workshop machinery, saws for logging and machines for the production of fodder. The following basic parameters were applied for the hygienic evaluation of noise: total monthly exposure and mean equivalent daily exposure expressed in Pa2 h. The study indicated that the highest values for total monthly exposure to noise were observed in 5 months, i.e. September, October, August, November and April. High total exposure values obtained in the summer-autumn months (August-November) are associated with the performance of such work activities as: harvesting of cereals and root plants, and cultivation of soil (characterised by the emission of sounds of high levels), with prolonged exposure to this factor and a large number of workdays in these months. In April, however, the occurrence of high total exposure values was due to intensive field activities (ploughing, harrowing, sowing), and prolonged exposure to this factor. In the seasons of the year analysed, high equivalent exposure values were observed within the range: 5.53-6.61 Pa2 h. Mean value for this parameter for the whole year reached the value of 4.27 Pa(2) h (standard exceeded 4.3 times). This value is equivalent to a mean exposure level equal to 91.3 dB. The results of studies of annual exposure to noise obtained by some other authors are close to the data presented in this report, and confirm that the degree of noise load clearly depends on the type of agricultural production and type of machines applied.

Giardia duodenalis infection and wastewater irrigation in Pakistan

The risk of Giardia duodenalis (Giardia) infection in farmers using untreated wastewater in agriculture was investigated in the city of Faisalabad, Pakistan, through a cross-sectional study. The study found a significantly increased risk of (asymptomatic) Giardia infection in wastewater farming households when compared with farming households using regular (non-wastewater) irrigation water (OR 3.3, 95% CI 2.5-4.4). Textile labourers who were employed in the city of Faisalabad but who lived in the same village as the wastewater farmers showed a risk of Giardia infection in between that of wastewater and non-wastewater farming households (OR 2.4, 95% CI 1.9-3.1). This study suggests that exposure to wastewater with high Giardia concentrations carries an increased risk for (asymptomatic) Giardia infection.