Agricultural Exposure Research Articles

Residential agricultural pesticide exposures and risk of selected congenital heart defects among offspring in the San Joaquin Valley of California

BackgroundPesticide exposures are ubiquitous and of substantial public concern. We examined the potential association of congenital heart defects with residential proximity to commercial agricultural pesticide applications in the San Joaquin Valley, California. MethodsStudy subjects included 569 heart defect cases and 785 non-malformed controls born from 1997 to 2006 whose mothers participated in a population-based case-control study. Associations with any versus no exposure to physicochemical groups of pesticides and specific chemicals were assessed using logistic regression adjusted for relevant covariates, for 8 heart defect phenotypes that included ≥50 cases and pesticide exposures with ≥5 exposed cases and controls, which resulted in 235 comparisons. Results38% of cases and controls were classified as exposed to pesticides within a 500m radius of mother׳s address during a 3-month periconceptional window. Adjusted odds ratios (AORs) with 95% CIs excluding 1.0 were observed for 18 comparisons; all were >1 and ranged from 1.9 to 7.1. They included tetralogy of Fallot (n=101 cases) and neonicotinoids; hypoplastic left heart syndrome (n=59) and strobins; coarctation of the aorta (n=74) and pyridazinones; pulmonary valve stenosis (n=53) and bipyridyliums and organophosphates; ventricular septal defects (n=93) and avermectins and pyrethroids; and atrial septal defects (n=132) and dichlorphenoxy acid or esters, organophosphates, organotins, and pyrethroids. No AORs met both of these criteria for d-transposition of the great arteries (n=58) or heterotaxia (n=53). ConclusionsMost pesticides were not associated with increased risk of specific heart defect phenotypes. For the few that were associated, results should be interpreted with caution until replicated in other study populations.

Responses of food production systems to climate change: sensitivity and vulnerability

Climate warming has prolonged the optimization of crop-growing seasons, shortened actual growth periods, and changed crop-planting boundaries. It also has boosted crop yields in certain regions while compromising crop quality and affected the occurrence of meteorological disasters and pest diseases damage, which has resulted in reduction in grain yield. Crop production systems will evidence more sensitivity to climate change in future; for example, with an increase of 1°C in temperature, the average growth period will be shortened by 17 days for winter wheat and 7–8 days for maize and rice. Of course regional differences will exist. Climate change will threaten crop yield stability and affect crop quality. Vulnerability will be addressed in regard to extreme climatic events, which include reducing exposure and improving adaptive capacity, because the exposure of rain-fed agriculture is greater than that of irrigated agriculture. Therefore, we propose three suggestions to reduce the vulnerability of crop p...

Assessing the Implications of Contradictory Farm Exposure Data in an Aging Rural Population

ABSTRACTOccupational exposure to agriculture can be measured in a variety of ways, including a simple yes/no classification, as well as continuous measures, such as years in farming. Regardless of the exposure measure, the possibility of mismeasurement exists. This can be the result of memory decay, differential interpretation, and overly broad definitions of farming. Data from a 20-year longitudinal study were used to measure the extent of this misclassification, and also to compare results obtained from yes/no measures (ever having farmed and current farmer) versus a more refined measure (years of farming). There were 1,811 households in a rural seven-county region of central New York responding to the survey. All subjects were ≥50 as of 2009. The subjects’ 2009 responses relating to agricultural exposure were validated against those given in 1989 and 1999. Subjects giving contradictory responses were contacted for clarification. Of the 445 subjects indicating any kind of agricultural exposure, 186 (41.8%) provided contradictory information. Correction of these led to a lower estimate of farming prevalence, but an increase in the mean years of farming. Contradictory responses were more common for females, subjects with partners, and those with better financial situations. For both the corrected and uncorrected data, ever farming, current farming, and years of farming were all strongly related to both farmer’s lung and farm machinery injury. Contradictory information is commonly encountered when measuring agricultural exposure. However, when studying measures that are strongly related to agriculture, the extra effort devoted to clarifying these contradictions may be unnecessary. For outcomes where these relationships are more subtle, correction may be more important.

Early pregnancy agricultural pesticide exposures and risk of gastroschisis among offspring in the San Joaquin Valley of California.

Prevalence of gastroschisis has inexplicably been increasing over the past few decades. Our intent was to explore whether early gestational exposures to pesticides were associated with risk of gastroschisis. We used population-based data, accompanied by detailed information from maternal interviews as well as information on residential proximity to a large number of commercial pesticide applications during early pregnancy. The study population derived from the San Joaquin Valley of California (). Cases were 156 infants/fetuses with gastroschisis and controls were 785 infants without birth defects. Among 22 chemical pesticide groups analyzed, none had an elevated odds ratio with an associated confidence interval that excluded 1.0, although exposure to the triazine group showed borderline significance. Among 36 specific pesticide chemicals analyzed, only exposure to petroleum distillates was associated with an elevated risk, odds ratio = 2.5 (1.1-5.6). In general, a substantially different inference was not derived when analyses were stratified by maternal age or when risk estimation included adjustment for race/ethnicity, body mass index, folic acid supplement use, and smoking. Our study rigorously adds to the scant literature on this topic. Our a priori expectation was that we would observe certain pesticide compounds to be particularly associated with young age owing to the disproportionate risk observed for young women to have offspring with gastroschisis. We did not observe an exposure profile unique to young women.

0286 Occupational use of insecticides, fungicides and fumigants and risk of non-Hodgkin lymphoma and multiple myeloma in the Agricultural Health Study0286 Occupational use of insecticides, fungicides and fumigants and risk of non-Hodgkin lymphoma and multiple myeloma in the Agricultural Health Study

ObjectivesFarming and exposure to pesticides have been linked to non-Hodgkin lymphoma (NHL), and multiple myeloma (MM) in previous studies. We evaluated use of insecticides, fungicides and fumigants and risk of...

0409 The North American Pooled Project (NAPP): Pooled analyses of case-control studies of pesticides and agricultural exposures, lymphohematopoietic cancers and sarcoma

ObjectivesPrevious studies have noted associations between specific pesticides and multiple cancer types. However, assessments for many pesticides have been limited by small numbers of exposed cases. To address this, we...

0206 Prostate cancer risk among French farmers in the AGRICAN cohort

ObjectivesProstate cancer is one of the most frequent cancers worldwide. Its aetiology is largely unknown with farming being suspected. Our aim was to identify occupational risk factors for prostate cancer...

Residential Agricultural Pesticide Exposures and Risk of Neural Tube Defects and Orofacial Clefts Among Offspring in the San Joaquin Valley of California

We examined whether early gestational exposures to pesticides were associated with an increased risk of anencephaly, spina bifida, cleft lip with or without cleft palate (CLP), or cleft palate only. We used population-based data along with detailed information from maternal interviews. Exposure estimates were based on residential proximity to agricultural pesticide applications during early pregnancy. The study population derived from the San Joaquin Valley, California (1997-2006). Analyses included 73 cases with anencephaly, 123 with spina bifida, 277 with CLP, and 117 with cleft palate only in addition to 785 controls. A total of 38% of the subjects were exposed to 52 chemical groups and 257 specific chemicals. There were relatively few elevated odds ratios with 95% confidence intervals that excluded 1 after adjustment for relevant covariates. Those chemical groups included petroleum derivatives for anencephaly, hydroxybenzonitrile herbicides for spina bifida, and 2,6-dinitroaniline herbicides and dithiocarbamates-methyl isothiocyanate for CLP. The specific chemicals included 2,4-D dimethylamine salt, methomyl, imidacloprid, and α-(para-nonylphenyl)-ω-hydroxypoly(oxyethylene) phosphate ester for anencephaly; the herbicide bromoxynil octanoate for spina bifida; and trifluralin and maneb for CLP. Adjusted odds ratios ranged from 1.6 to 5.1. Given that such odds ratios might have arisen by chance because of the number of comparisons, our study showed a general lack of association between a range of agricultural pesticide exposures and risks of selected birth defects.

Shifted T-cell polarisation after agricultural dust exposure in mice and men

RationaleA low prevalence of asthma and atopy has been shown in farmers and agricultural workers. However, in these workers, a higher prevalence of respiratory symptoms has been reported, in which...

Asymmetry in noise-induced hearing loss: evaluation of two competing theories.

Competing theories exist about why asymmetry is observed in noise-induced hearing loss (NIHL). We evaluated these theories using a cohort of young workers studied over 16 years. The study aim was to describe and evaluate patterns of hearing loss and asymmetry by gender, agricultural exposure and gunfire exposure. This was a secondary analysis of data collected from young adults during follow-up of a randomized controlled trial. This follow-up study evaluated long-term effects of a hearing conservation intervention for rural students. The sample consisted of 392 of 690 participants from the original trial. In total, 355 young adults (aged 29-33 years) completed baseline and follow-up noise exposure surveys and clinical audiometric examinations. Data are displayed graphically as thresholds by frequency and ear and degree of asymmetry between ears (left minus right). In the primary group comparisons, low and high frequency averages and mean high frequency asymmetry were analyzed using mixed linear models. At frequencies >2000 Hz, men showed more hearing loss, with greater asymmetry and a different asymmetry pattern, than women. For men with documented hearing loss, there was a trend toward increasing asymmetry with increasing levels of hearing loss. Asymmetry at high frequencies varied substantially by level of shooting exposure. While "head shadowing" is accepted as the primary explanation for asymmetric hearing loss in the audiologic and related public health literature, our findings are more consistent with physiological differences as the primary cause of asymmetric hearing loss, with greater susceptibility to NIHL in the left ear of men.

Risk factors for reduced glomerular filtration rate in a Nicaraguan community affected by Mesoamerican nephropathy.

Mesoamerican nephropathy, also known as chronic kidney disease of unknown etiology, is widespread in Pacific coastal Central America. The cause of the epidemic is unknown, but the disease may be linked to multiple factors, including diet as well as environmental and occupational exposures. As many as 50% of men in some communities have Mesoamerican nephropathy. Describe prevalence of reduced glomerular filtration rate in a region of Nicaragua suspected to harbor high rates of Mesoamerican nephropathy; and investigate potential risk factors for such reduction associated with agricultural work (such as pesticide exposure and specific agricultural tasks associated with increased heat stress); sugar consumption; and traditional factors such as age, sex, diabetes, hypertension and nephrotoxic medication use. This study uses a cross-sectional design with nested case-control analysis. Cases were individuals with estimated glomerular filtration rates of <60mL/min/1.73m2 and controls were individuals with those >90mL/min/1.73m2, estimated using serum creatinine. Data on nutrition, past medical history, medication and substance use, and agricultural behaviors and exposures were collected using medical questionnaires from June through August, 2012. Venous blood and urine samples were collected to assess hemoglobin A1c, and dipstick proteinuria, respectively; anthropometry and blood pressure measurements were made using standard techniques. Analyses were conducted using chi square, and univariate and multiple logistic regression. Of 424 individuals in the study, 151 had an occupational history in agriculture. Prevalence of glomerular filtration rate <60mL/min/1.73m2 was 9.8% among women and 41.9% among men (male to female ratio = 4.3, p<0.0001). Proteinuria =300 mg/dL was observed in <10% of participants with decreased glomerular filtration rate. Hemoglobin A1c and use of NSAIDs were not associated with decreased glomerular filtration rate. Although systolic and diastolic blood pressure was higher among participants with decreased glomerular filtration rate (p <0.001), hypertension was uncommon. Significant agricultural risk factors for reduced glomerular filtration rate included increased lifetime days cutting sugarcane during the dry season (OR 5.86, 95% CI 2.45-14.01), nondeliberate pesticide inhalation (OR 3.31, 95% CI 1.32-8.31), and sugarcane chewing (OR 3.24, 95% CI 1.39-7.58). Our findings demonstrate a high prevalence of chronic kidney disease not linked to traditional risk factors, and suggest it may be associated instead with occupational exposure to heat stress in conjunction with pesticide inhalation, sugarcane chewing and sugar intake during the workday.

Induction of mild therapeutic hypothermia in treatment of aluminium phosphide poisoning; an experimental study

Background: Exposure to aluminium phosphide (ALP) is a common cause of poisoning from agricultural pesticide exposures in some parts of the world. The absence of a specific antidote results in very high mortality due to acute ALP poisoning. The effect of induction of mild therapeutic hypothermia (MTH) on survival during poisoning from a lethal dose of ALP has been evaluated in the present study. Materials and methods: Male Sprague-Dawley rats were randomly divided into 4 groups. The first group received only the vehicle of ALP. The second group (SHAM group) received no drug. The third and the fourth group were given ALP in LD50 dose by gavage with an orogastric cannula. The core body temperature of animals in the fourth group was kept in the 32–35 degree centigrade range during the experiment (24 hours). The survival rate and histopathology of liver and kidney were used to evaluate outcomes. Findings: Mean survival time in group 3 was 9.143 hours (3.527–14.759; 95% CI), while it was 18.182 (14.730–21.634; 95% CI) in group 4. A Kaplan–Meier test showed that the difference between the groups was statistically significant (chi-square 15.408, p-value = 0.0001). The treatment group also experienced less histopathologic change attributed to ALP poisoning in their kidney and liver compared to the control group. However, only the difference in kidney histopathology was statistically significant (p-value = 0.016). Conclusion: Results of the current study showed that MTH may be beneficial in the treatment of acute ALP poisoning in rats in terms of survival rate and histopathologic changes in kidney and liver. Conducting experiments in humans is suggested in order to determine its true therapeutic value.

Integrating Agricultural Risks Management Strategies in Selected EU Partner Countries: Syria, Tunisia, Turkey

Dynamics and transitions in the agricultural sector of emerging countries are not well understood yet. A decade of major political and economic changes is challenging the Mediterranean Economies, affecting the primary sectors of transition economies which are largely influenced by recent trends. The resulting exposure of agriculture to risks has called great attention on risk management strategies and public intervention. We explore their role in three different economies with a view to a unified policy framework. The analysis is conducted through a field activity in Syria, Tunisia and Turkey that has allowed understanding the key issues. The experts’ opinions draw a clear picture of retrospect and prospects and stimulate a comparative analysis that widens the current knowledge of risk management in the EU Partner Countries.

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Introduction: We report the case of a 3 y/o boy with fever, headache, abdominal pain, decreased appetite who was being treated for presumed pneumonia and was found to have hepatomegaly, lymphadenopathy, hyperleukocytosis of 234,000 cells with 91% blasts, hemoglobin of 4.2 and platelets less than 5000. On transfer to our PICU, he was mechanically ventilated for respiratory failure and had plasmapheresis to prevent hyperviscocity syndrome. He was diagnosed with Pre B cell ALL and received chemotherapy per AALL1123 protocol. He was treated with piperacillin/tazobactam and azithromycin for pneumonia and bactrim and fluconazole for prophylaxis against opportunistic infections. He was extubated after 7days. On day 12 of induction chemotherapy, he had decreased responsiveness when CT brain revealed multiple areas of low density with surrounding vasogenic edema suspicious for fungal abscess or hemorrhage. MR spectroscopy result was suspicious for angioinvasive aspergillosis with associated abscesses. Amphotericin and voriconazole were used to treat presumed aspergillus infection. Stereotaxic guided craniotomy was done for biopsy of the brain lesion, which grew Aspergillus Fumigatus. Repeat CT scan of brain 4 and 6days after MRI showed worsening lesions and no improvement despite aggressive antifungal therapy. He died one month after his admission due to aspergillus brain abscess involving multiple areas of the brain including brain stem. Invasive aspergillosis(IA) is an important cause of morbidity and mortality in immunocompromised children with highest incidence found in children with Wiskott-Aldrich syndrome and a very low incidence of 0.6% in children with ALL. Aspergillus fumigatus is the most common cause of IA followed by aspergillus flavus, aspergillus niger, aspergillus terreus. Clinical practice guidelines of the Infectious disease society of America does not recommend empirical therapy in shorter duration of neutropenia <10days unless there are findings of invasive fungal infections. Our patient presented with hyperleukocytosis and likely had dysfunctional neutrophil function thus predisposing him to IA. He also progressed to absolute neutropenia in rapid fashion within 3days of initiation of chemotherapy. The most significant risk factor contributing to his development of IA may have been his home environment. The family lived and worked in Avondale Pennsylvania, a suburb of Philadelphia in chester County with close proximity to Kennet Square and its large mushroom farming industry. Kennet Square is noted as "The Mushroom Capital of the World" supplying over 51% of the nation's mushroom crop. Mushrooms as with other fungi, thrive in warm moist dark environment and are frequently fertilized with a soil/manure compost that is frequently rotated by heavy equipment. This compost rotation releases spores into the air that are harmless when inhaled by immunocompetent individuals. Our patient living in this endemic area was likely exposed to high spore content of pathogenic Aspergillus species environmentally and so rapidly developed brain abscess when chemotherapy was initiated. Our case is unique as he had very rapid onset of CNS aspergillosis, with history of agricultural exposure in the setting of Pre B cell ALL. Given our hospital's geographic location, questions remain whether consideration should be given to initiate empirical antifungal therapy at treatment doses with initiation of chemotherapy.

Organic Dust, Lipopolysaccharide, and Peptidoglycan Inhalant Exposures Result in Bone Loss/Disease

Skeletal health consequences associated with chronic inflammatory respiratory disease, and particularly chronic obstructive pulmonary disease (COPD), contribute to overall disease morbidity. Agricultural environmental exposures induce significant airway diseases, including COPD. However, animal models to understand inhalant exposure-induced lung injury and bone disease have not been described. Using micro-computed tomography (micro-CT) imaging technology and histology, bone quantity and quality measurements were investigated in mice after repetitive intranasal inhalation exposures to complex organic dust extracts (ODEs) from swine confinement facilities. Comparison experiments with LPS and peptidoglycan (PGN) alone were also performed. After 3 weeks of repetitive ODE inhalation exposure, significant loss of bone mineral density and trabecular bone volume fraction was evident, with altered morphological microarchitecture changes in the trabecular bone, compared with saline-treated control animals. Torsional resistance was also significantly reduced. Compared with saline treatment, ODE-treated mice demonstrated decreased collagen and proteoglycan content in their articular cartilage, according to histopathology. Significant bone deterioration was also evident after repetitive intranasal inhalant treatment with LPS and PGN. These findings were not secondary to animal distress, and not entirely dependent on the degree of induced lung parenchymal inflammation. Repetitive LPS treatment demonstrated the most pronounced changes in bone parameters, and PGN treatment resulted in the greatest lung parenchymal inflammatory changes. Collectively, repetitive inhalation exposures to noninfectious inflammatory agents such as complex organic dust, LPS, and PGN resulted in bone loss. This animal model may contribute to efforts toward understanding the mechanisms and evaluating the therapeutics associated with adverse skeletal health consequences after subchronic airway injury.

An evaluation of metrics for assessing maternal exposure to agricultural pesticides

We evaluate the use of three different exposure metrics to estimate maternal agricultural pesticide exposure during pregnancy. Using a geographic information system-based method of pesticide exposure estimation, we combine data on crop density and specific pesticide application amounts/dates to create the three exposure metrics. For illustration purposes, we create each metric for a North Carolina cohort of pregnant women, 2003-2005, and analyze the risk of congenital anomaly development with a focus on metric comparisons. Based on the results, and the need to balance data collection efforts/computational efficiency with accuracy, the metric which estimates total chemical exposure using application dates based on crop-specific earliest planting and latest harvesting information is preferred. Benefits and drawbacks of each metric are discussed and recommendations for extending the analysis to other states are provided.

Age, chronic lymphocytic leukemia, and agent orange exposure: A ten-year review

Introduction: Exposure to Agent Orange has been associated with the development of chronic lymphocytic leukemia (CLL). From 1962-1971, this agent was sprayed in Southeast Asia to destroy jungle, as part of the military effort. In 2002, the Department of Veterans Affairs added CLL to the list of diseases associated with Agent Orange (AO) exposure, based upon data from agricultural exposure suggesting a causative association.

Agricultural exposure and asthma risk in the AGRICAN French cohort

Epidemiological studies have reported an increased risk of respiratory diseases in agricultural population, but a protective "farm-effect" has also been reported for asthma. In the AGRICAN cohort, self-reported doctor-diagnosed asthma was analyzed according to allergy, in relation with history of life-time exposure to 13 crops and 5 livestock, pesticide exposure and early life on a farm, taking into account sex, age, education and body mass index. Among the 1246 asthmatics (8.0%), 505 were allergic (3.3%) and 719 non-allergic (4.6%). In multivariate analysis, a significant excess was observed, only for allergic asthma, in vine-growing (OR=1.43, p=0.002), fruit-growing (OR=1.58, p=0.001), greenhouses (OR=1.66, p=0.02), grasslands (OR=1.35, p=0.009), beets (OR=1.52, p=0.003) and horses (OR=1.35, p=0.04). Pesticide use and history of pesticide poisoning were significantly associated with allergic asthma in grassland, vineyards and fruit-growing and with non-allergic asthma in beets. Living on a farm in the first year of life tended to be protective for childhood allergic asthma in farms with livestock (OR=0.72, p=0.07) but deleterious in farms with vineyards, fruit or vegetables (OR=1.44, p=0.07). In AGRICAN, an increased risk of allergic asthma was observed with crop exposure, pesticide use and early life on a farm, especially in vine-growing, grassland, beets, fruit and vegetable-growing.

380 Multiple pesticide exposures and the risk of multiple myeloma in Canadian men

ObjectivesMultiple myeloma (MM) has been linked to certain agricultural exposures, including pesticides, however the effects of exposure to multiple pesticides have not been explored. This analysis investigated the association between...

305 Engine exhaust exposure and lung cancer risk in farming

ObjectivesFarmers have lower lung cancer rates than the general population, due to lower rates of smoking and possibly exposure to endotoxins. Farmers do, however, have exposure to potential lung carcinogens...