Agricultural Exposure Research Articles

Farmers’ attitude towards the use of USG in rice cultivation in three selected villages of Netrakona district

The study was conducted to determine the attitude of farmers towards the use of urea super granule (USG) in rice cultivation and explore relationship between the selected characteristics of the farmers. Data were collected through personal interview from 84 randomly selected USG users in rice cultivation of the three villages under Sadar Upazila of Netrakona district during October to December 2008. A five point Likert scale was used to determine the attitude of farmers. The majority (73.81%) of the farmers had moderately favourable, 21.43% slightly favourable and 4.76% highly favourable attitude towards use of USG in rice cultivation. Level of education, farm size, annual income, farming information, agricultural training exposure and rice farming knowledge of the farmers’ had significant positive relationship but family subsistence pressure had significant negative relationship with their attitude towards the use of USG. DOI: http://dx.doi.org/10.3329/jbau.v9i2.10983 J. Bangladesh Agril. Univ. 9(2): 179–185, 2011

Small-area analyses of bone cancer diagnosed in Great Britain provide clues to aetiology

BackgroundThe aetiology of bone cancers is poorly understood. This study examined geographical patterning in incidence of primary bone cancers diagnosed in 0–49 year olds in Great Britain during 1980–2005 to provide information on factors linked with disease development. We investigated putative associations with deprivation and population density.MethodsData on osteosarcoma and Ewing sarcoma were obtained from national population-based registries. Negative binomial regression was used to examine the relationship between incidence rates and the Townsend deprivation score (and its component variables) and small-area population density.ResultsThe study analyzed 2566 osteosarcoma and 1650 Ewing sarcoma cases. For females with osteosarcoma, statistically significant decreased risk was associated with higher levels of deprivation (relative risk [RR] per unit increase in deprivation score = 0.969; 95% confidence interval [CI] 0.946–0.993). For all Ewing sarcoma combined, statistically significant decreased risk was associated with greater area-level population density and higher levels of non-car ownership (RR per person per hectare increase = 0.984; 95% CI 0.976–0.993, RR per 1% increase in non-car ownership = 0.994; 95% CI 0.991–0.998).ConclusionsHigher incidence of osteosarcoma was observed for females in areas with lower deprivation levels indicating increased risk is linked to some aspect of affluent living. Higher incidence of Ewing sarcoma occurred in areas of low population density and where more people owned cars, both characteristic of rural environments. The study adds substantially to evidence associating Ewing sarcoma risk with rural environmental exposures. Putative risk factors include agricultural exposures, such as pesticides and zoonotic agents.

Using multiple imputation to assign pesticide use for non-responders in the follow-up questionnaire in the Agricultural Health Study

The Agricultural Health Study (AHS), a large prospective cohort, was designed to elucidate associations between pesticide use and other agricultural exposures and health outcomes. The cohort includes 57,310 pesticide applicators who were enrolled between 1993 and 1997 in Iowa and North Carolina. A follow-up questionnaire administered 5 years later was completed by 36,342 (63%) of the original participants. Missing pesticide use information from participants who did not complete the second questionnaire impedes both long-term pesticide exposure estimation and statistical inference of risk for health outcomes. Logistic regression and stratified sampling were used to impute key variables related to the use of specific pesticides for 20,968 applicators who did not complete the second questionnaire. To assess the imputation procedure, a 20% random sample of participants was withheld for comparison. The observed and imputed prevalence of any pesticide use in the holdout dataset were 85.7% and 85.3%, respectively. The distribution of prevalence and days/year of use for specific pesticides were similar across observed and imputed in the holdout sample. When appropriately implemented, multiple imputation can reduce bias and increase precision and can be more valid than other missing data approaches.

Breast Cancer Risk, Fungicide Exposure and CYP1A1*2A Gene-Environment Interactions in a Province-Wide Case Control Study in Prince Edward Island, Canada

Scientific certainty regarding environmental toxin-related etiologies of breast cancer, particularly among women with genetic polymorphisms in estrogen metabolizing enzymes, is lacking. Fungicides have been recognized for their carcinogenic potential, yet there is a paucity of epidemiological studies examining the health risks of these agents. The association between agricultural fungicide exposure and breast cancer risk was examined in a secondary analysis of a province-wide breast cancer case-control study in Prince Edward Island (PEI) Canada. Specific objectives were: (1) to derive and examine the level of association between estimated fungicide exposures, and breast cancer risk among women in PEI; and (2) to assess the potential for gene-environment interactions between fungicide exposure and a CYP1A1 polymorphism in cases versus controls. After 1:3 matching of 207 cases to 621 controls by age, family history of breast cancer and menopausal status, fungicide exposure was not significantly associated with an increased risk of breast cancer (OR = 0.74; 95% CI: 0.46–1.17). Moreover, no statistically significant interactions between fungicide exposure and CYP1A1*2A were observed. Gene-environment interactions were identified. Though interpretations of findings are challenged by uncertainty of exposure assignment and small sample sizes, this study does provide grounds for further research.

From forest to farm: systematic review of cultivar feeding by chimpanzees--management implications for wildlife in anthropogenic landscapes.

Crop-raiding is a major source of conflict between people and wildlife globally, impacting local livelihoods and impeding conservation. Conflict mitigation strategies that target problematic wildlife behaviours such as crop-raiding are notoriously difficult to develop for large-bodied, cognitively complex species. Many crop-raiders are generalist feeders. In more ecologically specialised species crop-type selection is not random and evidence-based management requires a good understanding of species' ecology and crop feeding habits. Comprehensive species-wide studies of crop consumption by endangered wildlife are lacking but are important for managing human–wildlife conflict. We conducted a comprehensive literature search of crop feeding records by wild chimpanzees (Pan troglodytes), a ripe-fruit specialist. We assessed quantitatively patterns of crop selection in relation to species-specific feeding behaviour, agricultural exposure, and crop availability. Crop consumption by chimpanzees is widespread in tropical Africa. Chimpanzees were recorded to eat a considerable range of cultivars (51 plant parts from 36 species). Crop part selection reflected a species-typical preference for fruit. Crops widely distributed in chimpanzee range countries were eaten at more sites than sparsely distributed crops. We identified ‘high’ and ‘low’ conflict crops according to their attractiveness to chimpanzees, taking account of their importance as cash crops and/or staple foods to people. Most (86%) high conflict crops were fruits, compared to 13% of low conflict crops. Some widely farmed cash or staple crops were seldom or never eaten by chimpanzees. Information about which crops are most frequently consumed and which are ignored has enormous potential for aiding on-the-ground stakeholders (i.e. farmers, wildlife managers, and conservation and agricultural extension practitioners) develop sustainable wildlife management schemes for ecologically specialised and protected species in anthropogenic habitats. However, the economic and subsistence needs of local people, and the crop-raiding behaviour of sympatric wildlife, must be considered when assessing suitability of particular crops for conflict prevention and mitigation.

Children's Safety on American Indian Farms: Information and Recommendations

ABSTRACT It is estimated that 1.2 million youth younger than age 20 live on farms; American Indian children constitute an important but understudied subset of this at-risk group. Despite documented risks of injuries and death among children who live and work on farms and a descending trend in the overall reported fatalities among youth who live and/or work on farms, very little is known about the agriculture-related injury and fatality experience of American Indian youth. Limited data indicate that drowning, motor vehicles, and poisonings are leading causes of unintentional mortality and morbidity for this group, although the attribution to agricultural exposure is not evident. The scant available data indicate a need to look more closely at agricultural work, bystander exposures, and other farm events that put American Indian youth at risk of illness, injury, or death compared to factors more fully reported for majority youth in the agriculture population, in order to guide intervention and prevention programs that are appropriate and acceptable to this vulnerable population.

Glyphosate Exposure in a Farmer’s Family

We tested the presence of glyphosate in the urines of a farmer who sprayed a glyphosate based herbicide on his land, and in his family, as his children were born with birth defects that could be due to or promoted by pesticides. Glyphosate residues were measured in urines a day before, during, and two days after spraying, by liquid chromatography-linear ion trap mass spectrometry. Glyphosate reached a peak of 9.5 µg/L in the farmer after spraying, and 2 µg/L were found in him and in one of his children living at a distance from the field, two days after the pulverization. Oral or dermal absorptions could explain the differential pesticide excretions, even in family members at a distance from the fields. A more detailed following of agricultural practices and family exposures should be advocated together with information and recommendations.

Occupational risk factors associated with Lymphoid Malignancies in Benin City, Nigeria

This study is designed to identify the associated occupations most at risk of developing lymphoid malignancies. The medical records of all lymphoid malignancy cases seen in University of Benin Teaching Hospital between July 2001 and June 2010 were retrieved from medical record library. The patient's bio-data, occupational, social and past medical history and pathologic subtypes were extracted. A total of 252 patients records with diagnosis of lymphoid malignancies were reviewed in this study. Farmers (20.6%) and students (38.9%) form the majority of the cases seen and both showed statistically significant association with risk of LM (p<0.0001) This study revealed that agricultural workers and students in Benin City are at higher risk of developing lymphoid malignancies. Although previous studies have implicated agricultural exposure, the same cannot be said about students. It is therefore recommended that a follow up study should be conducted to ascertain the possible environmental, nutritional, social/lifestyle stressors that put students in Benin City at higher risk of lymphoid malignancies.

Modelling effects of chemical exposure on birds wintering in agricultural landscapes: The western burrowing owl ( Athene cunicularia hypugaea) as a case study

We describe an ecotoxicological model that simulates the sublethal and lethal effects of chronic, low-level, chemical exposure on birds wintering in agricultural landscapes. Previous models estimating the impact on wildlife of chemicals used in agro-ecosystems typically have not included the variety of pathways, including both dermal and oral, by which individuals are exposed. The present model contains four submodels simulating (1) foraging behavior of individual birds, (2) chemical applications to crops, (3) transfers of chemicals among soil, insects, and small mammals, and (4) transfers of chemicals to birds via ingestion and dermal exposure. We demonstrate use of the model by simulating the impacts of a variety of commonly used herbicides, insecticides, growth regulators, and defoliants on western burrowing owls ( Athene cunicularia hypugaea) that winter in agricultural landscapes in southern Texas, United States. The model generated reasonable movement patterns for each chemical through soil, water, insects, and rodents, as well as into the owl via consumption and dermal absorption. Sensitivity analysis suggested model predictions were sensitive to uncertainty associated with estimates of chemical half-lives in birds, soil, and prey, sensitive to parameters associated with estimating dermal exposure, and relatively insensitive to uncertainty associated with details of chemical application procedures (timing of application, amount of drift). Nonetheless, the general trends in chemical accumulations and the relative impacts of the various chemicals were robust to these parameter changes. Simulation results suggested that insecticides posed a greater potential risk to owls of both sublethal and lethal effects than do herbicides, defoliants, and growth regulators under crop scenarios typical of southern Texas, and that use of multiple indicators, or endpoints provided a more accurate assessment of risk due to agricultural chemical exposure. The model should prove useful in helping prioritize the chemicals and transfer pathways targeted in future studies and also, as these new data become available, in assessing the relative danger to other birds of exposure to different types of agricultural chemicals.

ENDOTOXIN EXPOSURE, TLR4 MUTATIONS, SMOKING, AND WORK-RELATED BEHAVIORS: PULMONARY FUNCTION DEFICITS AMONG POTENTIALLY SUSCEPTIBLE SUBGROUPS OF AGRICULTURAL WORKERS IN COLORADO AND NEBRASKA

Background and Aims: Organic dust inhalation has been associated with adverse respiratory responses among agricultural workers. Susceptibility to the adverse health effects resulting from these agricultural exposures may be related to: constituents of the dust, e.g. endotoxin; intrinsic factors, e.g. genetic traits; and extrinsic factors, e.g. smoking and work-related behaviors. Methods: This study quantified breathing-zone personal work shift exposures to inhalable dust, endotoxin, and its 3-hydroxy fatty acid (3-OHFA) constituents, and evaluated pulmonary function before and after the work shift among 136 cattle feedlot, dairy, grain elevator, and corn farm workers. General linear models were used to assess the multivariable relationships between dust exposures and lung function (forced vital capacity, FVC; forced expiratory volume in 1 second, FEV1; and the FEV1/FVC ratio). Genotyping of SNPs in two polymorphisms in the TLR4 gene (TLR4 299 and 399) was performed. Results: Geometric mean dust levels were similar among feedlot (1.53mg/m3; n=59), dairy (1.45mg/m3; n=15), and farm (1.58mg/m3; n=9) employees and elevated among grain elevator operators (2.03mg/m3; n=53). Endotoxin concentrations were similar across all facility types. Increased dust exposure was associated with work shift decrements in FVC and FEV1. These relationships were stronger among current smokers and those reporting application of pesticides/herbicides at work or home (interactions between dust and smoking and between dust and pesticide use, p•0.05); however, no evidence of increased susceptibility was observed among those living on a farm. Interactions between dust/endotoxin exposures and genetic mutations were observed (p&lt;0.05), although the small number of participants with genetic mutations limits interpretation. Further analyses will identify additional factors that may confer increased susceptibility to the adverse pulmonary effects (crossshift and pre-shift) of agricultural exposures. Conclusions: A better understanding of factors leading to increased susceptibility for the development of adverse respiratory outcomes is needed to optimize prevention strategies among agricultural workers.

RISK OF PARKINSON’S DISEASE AND AGRICULTURAL PESTICIDE EXPOSURE

Background and Aims: Several studies have found an association between agricultural pesticide exposure and Parkinson’s disease (PD), but uncertainties remain about the characteristics of exposure t...

PREGNANCY, EXPOSURE TO PESTICIDES AND INFANT LEUKEMIA IN BRAZIL

Background and Aims: Infant leukemia (IL) is a rare hematological neoplasm associated with MLL gene rearrangements. Maternal exposures during pregnancy to pesticides, hormones, dipyrone, and topoisomerase-II DNA inhibitors and high birth weight were associated risk factors. Methods: This is a hospital-based multicenter case-control study. Mothers of 252 IL cases and 423 controls were interviewed and data were obtained regarding environmental maternal exposure during periconceptional, pregnancy and breast-feeding periods, including exposure to pesticides. Unconditional logistic regression was performed and odds ratios (OR) on the association between maternal pesticides exposure and IL, including their 95% confidence intervals (CI), were ascertained after adjustment to hormonal intake during pregnancy, mother’s age, mother’s level of education, birth weight and infant’s skin color. Results: An adjusted OR, 2.39, 95% CI, 1.63-3.51 was observed for the association between IL and maternal exposure to pesticides during pregnancy, being higher for acute myeloid leukemia (adjusted OR 3.50, 95% CI, 2.01-6.11). The use of pyrethroids during pregnancy revealed an OR 2.18 (95% CI, 1.44-3.29), while the use of other pesticides showed an OR 3.61 (95% CI, 1.69-7.73). The reported household use of pesticides revealed an adjusted OR 2.25 (95% CI, 1.48-3.43), and agriculture exposure showed an adjusted OR 9.26, (95% CI, 2.82-30.4). According to frequency of exposure, an adjusted OR, 2.48 (95% CI, 1.50 - 4.00) was seem among those reporting up to 1 contact weekly, and an adjusted OR 2.34 (95% CI, 1.30– 4.21) among those with &gt; 1 contact (p-trend &lt; 0.0001). Mixed exposure to different pesticides showed an adjusted OR, 3.83 (95% CI, 1.33-11.0) and the exposure to different chemical classes revealed an adjusted OR, 8.87 (95% CI, 1.55-50.6). Conclusions: The observed results seem to support the hypothesis that mothers’ household use of pesticides and other contaminants may be involved in the etiology of infant leukemia.

Crop exposures and chronic bronchitis among farmers in the Agriculture and Cancer cohort

ObjectivesLivestock farming is a well-known risk factor for chronic bronchitis (CB) but crop farming as a risk factor has been much less studied.MethodsThe Agriculture and Cancer cohort included ≈184 000...

Climate change, agricultural insecticide exposure, and risk for freshwater communities

Climate change exerts direct effects on ecosystems but has additional indirect effects due to changes in agricultural practice. These include the increased use of pesticides, changes in the areas that are cultivated, and changes in the crops cultivated. It is well known that pesticides, and in particular insecticides, affect aquatic ecosystems adversely. To implement effective mitigation measures it is necessary to identify areas that are affected currently and those that will be affected in the future. As a consequence, we predicted potential exposure to insecticide (insecticide runoff potential, RP) under current conditions (1990) and under a model scenario of future climate and land use (2090) using a spatially explicit model on a continental scale, with a focus on Europe. Space-for-time substitution was used to predict future levels of insecticide application, intensity of agricultural land use, and cultivated crops. To assess the indirect effects of climate change, evaluation of the risk of insecticide exposure was based on a trait-based, climate-insensitive indicator system (SPEAR, SPEcies At Risk). To this end, RP and landscape characteristics that are relevant for the recovery of affected populations were combined to estimate the ecological risk (ER) of insecticides for freshwater communities. We predicted a strong increase in the application of, and aquatic exposure to, insecticides under the future scenario, especially in central and northern Europe. This, in turn, will result in a severe increase in ER in these regions. Hence, the proportion of stream sites adjacent to arable land that do not meet the requirements for good ecological status as defined by the EU Water Framework Directive will increase (from 33% to 39% for the EU-25 countries), in particular in the Scandinavian and Baltic countries (from 6% to 19%). Such spatially explicit mapping of risk enables the planning of adaptation and mitigation strategies including vegetated buffer strips and nonagricultural recolonization zones along streams.

AGRICOH, a newly formed consortium of agricultural cohorts

ObjectivesWe recently formed AGRICOH, a consortium of agricultural cohort studies, offering the opportunity to investigate potential health effects of a wide range of occupational and environmental exposures coexisting in agriculture.Methods...

Carbofuran occupational dermal toxicity, exposure and risk assessment

BACKGROUNDCarbofuran is a carbamate insecticide that inhibits AChE. Although toxic by ingestion in mammals, it has low dermal toxicity, with relatively few confirmed worker illnesses. This risk assessment describes its time of onset, time to peak effect and time to recovery in rats using brain AChE inhibition in acute and 21 day dermal studies; in vitro rat/human relative dermal absorption for granular (5G) and liquid (4F) formulations; occupational exposure estimates using the Pesticide Handlers' Exposure Database and Agricultural Handlers' Exposure Database (PHED/AHED).RESULTSThe point of departure for acute risk calculation (BMDL10) was 6.7 mg kg−1 day−1 for brain AChE inhibition after 6 h exposure. In a 21 day study, the BMDL10 was 6.8 mg kg−1 day−1, indicating reversibility. At 75 mg kg−1 day−1, time of onset was ≤30 min and time to peak effect was 6–12 h. Rat skin had ca tenfold greater dermal absorption of carbofuran (Furadan® 5G or 4F) than human skin. Exposure estimates for 5G in rice and 4F in ten crops had adequate margins of exposure (>100).CONCLUSIONRat dermal carbofuran toxicity was assessed in terms of dose and time-related inhibition of AChE. Comparative dermal absorption in rats was greater than in humans. Worker exposure estimates indicated acceptable risk for granular and liquid formulations of carbofuran. Copyright © 2011 Society of Chemical Industry

P2-82 Pregnancy, exposure to pesticides and infant leukaemia in Brazil

Infant Leukaemia is a rare haematological neoplasm associated with MLL gene rearrangements. Maternal exposure during pregnancy to pesticides, hormones, dipyrone, and topoisomerase-II DNA inhibitors and birth weight were associated risk...

Exposure to multiple pesticides and risk of non-Hodgkin lymphoma in men from six Canadian provinces.

Non-Hodgkin lymphoma (NHL) has been linked to several agricultural exposures, including some commonly used pesticides. Although there is a significant body of literature examining the effects of exposure to individual pesticides on NHL, the impact of exposure to multiple pesticides or specific pesticide combinations has not been explored in depth. Data from a six-province Canadian case-control study conducted between 1991 and 1994 were analyzed to investigate the relationship between NHL, the total number of pesticides used and some common pesticide combinations. Cases (n = 513) were identified through hospital records and provincial cancer registries and controls (n = 1,506), frequency matched to cases by age and province of residence, were obtained through provincial health records, telephone listings, or voter lists. In multiple logistic regression analyses, risk of NHL increased with the number of pesticides used. Similar results were obtained in analyses restricted to herbicides, insecticides and several pesticide classes. Odds ratios increased further when only ‘potentially carcinogenic’ pesticides were considered (OR[one pesticide] = 1.30, 95% CI = 0.90–1.88; OR[two to four] = 1.54, CI = 1.11–2.12; OR[five or more] = 1.94, CI = 1.17–3.23). Elevated risks were also found among those reporting use of malathion in combination with several other pesticides. These analyses support and extend previous findings that the risk of NHL increases with the number of pesticides used and some pesticide combinations.

Comparison of skin prick allergy test in urban and rural children

Background Children who grow up in rural areas have a lower incidence of atopy and other allergic manifestations than children in urban areas. Several recent studies have suggested that agricultural exposure may protect children from developing asthma and atopy, but these findings are inconsistent.Objective To examine an association between living in rural or urban areas and skin prick allergy test results in children and to detennine associated risk factors for atopy.Methods We conducted a cross-sectional study in Karo district (rural) and Medan (urban) in October-December 2009. We enrolled primary school children who had a history of atopy in their families. Skin prick testing was done on the volar side of the forearm and included eight aero-allergens: house dust mites, house dust, cotton, chicken feathers, cat dander, cockroaches, mould, and pollen. We analyzed the folloMng risk factors forassociation Mth atopy: tobacco smoke, pets, livestock exposure, and having older sibling(s).Results We recruited 49 children from the Karo district and 52 children from the city of Medan. There were significant associations between living in an urban area and positive skin prick test results for house dust mites and house dust compared to living in a rural area (P=0.04, 95% CI: 1.11 to 5.91; P=0.04, 95% CI: 1.13 to 12.45, respectively). The reverse was true for cockroach allergens (P=0.02, 95% CI: 0.16 to 0.81). Tobacco smoke and livestock exposure were associated Mth negative skin prick test results in rural children (P=O.03, 95% CI: 0.03 to 0.81 and P=0.002, 95% CI: 0.02 to 0.42, respectively). Multivariate analysis revealed that lack of livestock exposure was the major risk factor associated Mth any positive skin prick test results in rural children (P=0.004; 95% CI ; 0.02 to 0.49).Conclusion There were differing associations between living in rural and urban areas to various skin prick test results in children. Lack of livestock exposure was the risk factor associated with positive skin prick test results in rural children.

AGRICOH: A Consortium of Agricultural Cohorts

AGRICOH is a recently formed consortium of agricultural cohort studies involving 22 cohorts from nine countries in five continents: South Africa (1), Canada (3), Costa Rica (2), USA (6), Republic of Korea (1), New Zealand (2), Denmark (1), France (3) and Norway (3). The aim of AGRICOH, initiated by the US National Cancer Institute (NCI) and coordinated by the International Agency for Research on Cancer (IARC), is to promote and sustain collaboration and pooling of data to investigate the association between a wide range of agricultural exposures and a wide range of health outcomes, with a particular focus on associations that cannot easily be addressed in individual studies because of rare exposures (e.g., use of infrequently applied chemicals) or relatively rare outcomes (e.g., certain types of cancer, neurologic and auto-immune diseases). To facilitate future projects the need for data harmonization of selected variables is required and is underway. Altogether, AGRICOH provides excellent opportunities for studying cancer, respiratory, neurologic, and auto-immune diseases as well as reproductive and allergic disorders, injuries and overall mortality in association with a wide array of exposures, prominent among these the application of pesticides.