Bibliography Tag: epidemiological studies

Curwin et al., 2002

Curwin, B., Sanderson, W., Reynolds, S., Hein, M., & Alavanja, M.; “Pesticide use and practices in an Iowa farm family pesticide exposure study;” Journal of Agricultural Safety and Health, 2002, 8(4), 423-433; DOI: 10.13031/2013.10222.

ABSTRACT:

Residents of Iowa were enrolled in a study investigating differences in pesticide contamination and exposure factors between 25 farm homes and 25 non-farm homes. The target pesticides investigated were atrazine, metolachlor, acetochlor, alachlor, 2,4-D, glyphosate, and chlorpyrifos; all were applied to either corn or soybean crops. A questionnaire was administered to all participants to determine residential pesticide use in and around the home. In addition, a questionnaire was administered to the farmers to determine the agricultural pesticides they used on the farm and their application practices. Non-agricultural pesticides were used more in and around farm homes than non-farm homes. Atrazine was the agricultural pesticide used most by farmers. Most farmers applied pesticides themselves but only 10 (59%) used tractors with enclosed cabs, and they typically wore little personal protective equipment (PPE). On almost every farm, more than one agricultural pesticide was applied. Corn was grown by 23 (92%) farmers and soybeans by 12 (48%) farmers. Of these, 10 (40%) grew both soybeans and corn, with only 2 (8%) growing only soybeans and 13 (52%) growing only corn. The majority of farmers changed from their work clothes and shoes in the home, and when they changed outside or in the garage, they usually brought their clothes and shoes inside. Applying pesticides using tractors with open cabs, not wearing PPE, and changing from work clothes in the home may increase pesticide exposure and contamination. Almost half of the 66 farm children less than 16 years of age were engaged in some form of farm chores, with 6 (9%) potentially directly exposed to pesticides, while only 2 (4%) of the 52 non-farm children less than 16 years of age had farm chores, and none were directly exposed to pesticides. Farm homes may be contaminated with pesticides in several ways, resulting in potentially more contamination than non-farm homes, and farm children may be directly exposed to pesticides through farm chores involving pesticides. In addition to providing a description of pesticide use, the data presented here will be useful in evaluating potential contributing factors to household pesticide contamination and family exposure. FULL TEXT


Thomas et al., 2010

Thomas, K. W., Dosemeci, M., Hoppin, J. A., Sheldon, L. S., Croghan, C. W., Gordon, S. M., Jones, M. L., Reynolds, S. J., Raymer, J. H., Akland, G. G., Lynch, C. F., Knott, C. E., Sandler, D. P., Blair, A. E., & Alavanja, M. C.; “Urinary biomarker, dermal, and air measurement results for 2,4-D and chlorpyrifos farm applicators in the Agricultural Health Study;” Journal of Exposure Science and Environmental Epidemiology, 2010, 20(2), 119-134; DOI: 10.1038/jes.2009.6.

ABSTRACT:

A subset of private pesticide applicators in the Agricultural Health Study (AHS) epidemiological cohort was monitored around the time of their agricultural use of 2,4-dichlorophenoxyacetic acid (2,4-D) and O,O-diethyl-O-3,5,6-trichloro-2-pyridyl phosphorothioate (chlorpyrifos) to assess exposure levels and potential determinants of exposure. Measurements included pre- and post-application urine samples, and patch, hand wipe, and personal air samples. Boom spray or hand spray application methods were used by applicators for 2,4-D products. Chlorpyrifos products were applied using spray applications and in-furrow application of granular products. Geometric mean (GM) values for 69 2,4-D applicators were 7.8 and 25 microg/l in pre- and post-application urine, respectively (P<0.05 for difference); 0.39 mg for estimated hand loading; 2.9 mg for estimated body loading; and 0.37 microg/m(3) for concentration in personal air. Significant correlations were found between all media for 2,4-D. GM values for 17 chlorpyrifos applicators were 11 microg/l in both pre- and post-application urine for the 3,5,6-trichloro-2-pyridinol metabolite, 0.28 mg for body loading, and 0.49 microg/m(3) for air concentration. Only 53% of the chlorpyrifos applicators had measurable hand loading results; their median hand loading being 0.02 mg. Factors associated with differences in 2,4-D measurements included application method and glove use, and, for hand spray applicators, use of adjuvants, equipment repair, duration of use, and contact with treated vegetation. Spray applications of liquid chlorpyrifos products were associated with higher measurements than in-furrow granular product applications. This study provides information on exposures and possible exposure determinants for several application methods commonly used by farmers in the cohort and will provide information to assess and refine exposure classification in the AHS. Results may also be of use in pesticide safety education for reducing exposures to pesticide applicators. FULL TEXT


Hoppin et al., 2002

Hoppin, Jane A., Umbach, David M, London, Stephanie J., Alavanja, Michael, & Sandler, Dale P.; “Chemical Predictors of Wheeze among Farmer Pesticide Applicators in the Agricultural Health Study;” American Journal of Respiratory and Critical Care Medicine, 2002, 165, 683-689; DOI: 10.1164/rccm.2106074.

ABSTRACT:

Pesticides may contribute to respiratory symptoms among farmers. Using the Agricultural Health Study, a large cohort of certified pesticide applicators in Iowa and North Carolina, we explored the association between wheeze and pesticide use in the past year. Self-administered questionnaires contained items on 40 currently used pesticides and pesticide application practices. A total of 20,468 applicators, ranging in age from 16 to 88 years, provided complete information; 19% reported wheezing in the past year. Logistic regression models controlling for age, state, smoking, and history of asthma or atopy were used to evaluate associations between individual pesticides and wheeze. Among pesticides suspected to contribute to wheeze, paraquat, three organophosphates (parathion, malathion, and chlorpyrifos), and one thiocarbamate (S-ethyl-dipropylthiocarbamate [EPTC]) had elevated odds ratios (OR). Parathion had the highest OR (1.5, 95% confidence interval [CI] 1.0, 2.2).

Chlorpyrifos, EPTC, paraquat, and parathion demonstrated significant dose–response trends. The herbicides, atrazine and alachlor, but not 2,4-D, were associated with wheeze. Atrazine had a significant dose–response trend with participants applying atrazine more than 20 days/year having an OR of 1.5 (95% CI 1.2,1.9). Inclusion of crops and animals into these models did not significantly alter the observed OR. These associations, though small, suggest an independent role for specific pesticides in respiratory symptoms of farmers. FULL TEXT


Dosemeci et al., 2002

Dosemeci, M., Alavanja, M. C., Rowland, A. S., Mage, D., Zahm, S. H., Rothman, N., Lubin, J. H., Hoppin, J. A., Sandler, D. P., & Blair, A.; “A quantitative approach for estimating exposure to pesticides in the Agricultural Health Study;” Annals of Occupational Hygiene, 2002, 46(2), 245-260; DOI: 10.1093/annhyg/mef011.

ABSTRACT:

We developed a quantitative method to estimate long-term chemical-specific pesticide exposures in a large prospective cohort study of more than 58000 pesticide applicators in North Carolina and Iowa. An enrollment questionnaire was administered to applicators to collect basic time- and intensity-related information on pesticide exposure such as mixing condition, duration and frequency of application, application methods and personal protective equipment used. In addition, a detailed take-home questionnaire was administered to collect further intensity-related exposure information such as maintenance or repair of mixing and application equipment, work practices and personal hygiene. More than 40% of the enrolled applicators responded to this detailed take-home questionnaire. Two algorithms were developed to identify applicators’ exposure scenarios using information from the enrollment and take-home questionnaires separately in the calculation of subject-specific intensity of exposure score to individual pesticides. The ‘general algorithm’ used four basic variables (i.e. mixing status, application method, equipment repair status and personal protective equipment use) from the enrollment questionnaire and measurement data from the published pesticide exposure literature to calculate estimated intensity of exposure to individual pesticides for each applicator. The ‘detailed’ algorithm was based on variables in the general algorithm plus additional exposure information from the take-home questionnaire, including types of mixing system used (i.e. enclosed or open), having a tractor with enclosed cab and/or charcoal filter, frequency of washing equipment after application, frequency of replacing old gloves, personal hygiene and changing clothes after a spill. Weighting factors applied in both algorithms were estimated using measurement data from the published pesticide exposure literature and professional judgment. For each study subject, chemical-specific lifetime cumulative pesticide exposure levels were derived by combining intensity of pesticide exposure as calculated by the two algorithms independently and duration/frequency of pesticide use from the questionnaire. Distributions of duration, intensity and cumulative exposure levels of 2,4-D and chlorpyrifos are presented by state, gender, age group and applicator type (i.e. farmer or commercial applicator) for the entire enrollment cohort and for the sub-cohort of applicators who responded to the take-home questionnaire. The distribution patterns of all basic exposure indices (i.e. intensity, duration and cumulative exposure to 2,4-D and chlorpyrifos) by state, gender, age and applicator type were almost identical in two study populations, indicating that the take-home questionnaire sub-cohort of applicators is representative of the entire cohort in terms of exposure. FULL TEXT


Alavanja et al., 1996

Alavanja, M. C., Sandler, D. P., McMaster, S. B., Zahm, S. H., McDonnell, C. J., Lynch, C. F., Pennybacker, M., Rothman, N., Dosemeci, M., Bond, A. E., & Blair, A.; “The Agricultural Health Study;” Environmental Health Perspectives, 1996, 104(4), 362-369; DOI: 10.1289/ehp.96104362.

ABSTRACT:

The Agricultural Health Study, a large prospective cohort study has been initiated in North Carolina and Iowa. The objectives of this study are to: 1) identify and quantify cancer risks among men, women, whites, and minorities associated with direct exposure to pesticides and other agricultural agents; 2) evaluate noncancer health risks including neurotoxicity reproductive effects, immunologic effects, nonmalignant respiratory disease, kidney disease, and growth and development among children; 3) evaluate disease risks among spouses and children of farmers that may arise from direct contact with pesticides and agricultural chemicals used in the home lawns and gardens, and from indirect contact, such as spray drift, laundering work clothes, or contaminated food or water; 4) assess current and past occupational and nonoccupational agricultural exposures using periodic interviews and environmental and biologic monitoring; 5) study the relationship between agricultural exposures, biomarkers of exposure, biologic effect, and genetic susceptibility factors relevant to carcinogenesis; and 6) identify and quantify cancer and other disease risks associated with lifestyle factors such as diet, cooking practices, physical activity, smoking and alcohol consumption, and hair dye use. In the first year of a 3-year enrollment period, 26,235 people have been enrolled in the study, including 19,776 registered pesticide applicators and 6,459 spouses of registered farmer applicators. It is estimated that when the total cohort is assembled in 1997 it will include approximately 75,000 adult study subjects. Farmers, the largest group of registered pesticide applicators comprise 77% of the target population enrolled in the study. This experience compares favorably with enrollment rates of previous prospective studies. FULL TEXT


Pardo et al., 2020

Pardo, L. A., Beane Freeman, L. E., Lerro, C. C., Andreotti, G., Hofmann, J. N., Parks, C. G., Sandler, D. P., Lubin, J. H., Blair, A., & Koutros, S.; “Pesticide exposure and risk of aggressive prostate cancer among private pesticide applicators;” Environmental Health, 2020, 19(1), 30; DOI: 10.1186/s12940-020-00583-0. https://www.ncbi.nlm.nih.gov/pubmed/32138787.

ABSTRACT:

BACKGROUND: Prostate cancer (PCa) is one of the most commonly diagnosed cancers among men in developed countries; however, little is known about modifiable risk factors. Some studies have implicated organochlorine and organophosphate insecticides as risk factors (particularly the organodithioate class) and risk of clinically significant PCa subtypes. However, few studies have evaluated other pesticides. We used data from the Agricultural Health Study, a large prospective cohort of pesticide applicators in North Carolina and Iowa, to extend our previous work and evaluate 39 additional pesticides and aggressive PCa.

METHODS: We used Cox proportional hazards models, with age as the time scale, to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between ever use of individual pesticides and 883 cases of aggressive PCa (distant stage, poorly differentiated grade, Gleason score >/= 7, or fatal prostate cancer) diagnosed between 1993 and 2015. All models adjusted for birth year, state, family history of PCa, race, and smoking status. We conducted exposure-response analyses for pesticides with reported lifetime years of use.

RESULTS: There was an increased aggressive PCa risk among ever users of the organodithioate insecticide dimethoate (n = 54 exposed cases, HR = 1.37, 95% CI = 1.04, 1.80) compared to never users. We observed an inverse association between aggressive PCa and the herbicide triclopyr (n = 35 exposed cases, HR = 0.68, 95% CI = 0.48, 0.95), with the strongest inverse association for those reporting durations of use above the median (>/= 4 years; n = 13 exposed cases, HR=0.44, 95% CI=0.26, 0.77).

CONCLUSION: Few additional pesticides were associated with prostate cancer risk after evaluation of extended data from this large cohort of private pesticide applicators.

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Lerro et al., 2020

Lerro, C. C., Hofmann, J. N., Andreotti, G., Koutros, S., Parks, C. G., Blair, A., Albert, P. S., Lubin, J. H., Sandler, D. P., & Beane Freeman, L. E.; “Dicamba use and cancer incidence in the agricultural health study: an updated analysis;” International Journal of Epidemiology, 2020; DOI: 10.1093/ije/dyaa066.

ABSTRACT:

BACKGROUND: The herbicide dicamba has been commonly used agriculturally and residentially. Recent approval of genetically engineered dicamba-resistant crops is expected to lead to increased dicamba use, and there has been growing interest in potential human health effects. A prior analysis in the Agricultural Health Study (AHS) suggested associations between dicamba and colon and lung cancer. We re-evaluated dicamba use in the AHS, including an additional 12 years and 2702 exposed cancers.

METHODS: The AHS is a prospective cohort of pesticide applicators in Iowa and North Carolina. At enrollment (1993–1997) and follow-up (1999–2005), participants reported dicamba use. Exposure was characterized by cumulative intensity-weighted lifetime days, including exposure lags of up to 20 years. We estimated relative risks (RR) and 95% confidence intervals (CI) using multivariable Poisson regression for incident cancers diagnosed from enrollment through 2014/2015.

RESULTS: Among 49 922 applicators, 26 412 (52.9%) used dicamba. Compared with applicators reporting no dicamba use, those in the highest quartile of exposure had elevated risk of liver and intrahepatic bile duct cancer (nexposed = 28, RRQ4 = 1.80, CI: 1.26–2.56, Ptrend < 0.001) and chronic lymphocytic leukaemia (CLL, nexposed = 93, RRQ4 = 1.20, CI: 0.96–1.50, Ptrend = 0.01) and decreased risk of myeloid leukaemia (nexposed = 55, RRQ4 = 0.73, CI: 0.51–1.03, Ptrend = 0.01). The associations for liver cancer and myeloid leukaemia remained after lagging exposure of up to 20 years.

CONCLUSIONS: With additional follow-up and exposure information, associations with lung and colon cancer were no longer apparent. In this first evaluation of liver and intrahepatic bile duct cancer, there was an association with increasing use of dicamba that persisted across lags of up to 20 years. FULL TEXT


Gray et al., 2000

Gray, George M., Goldstein, Bernard D., Bailar, John, Davis, Devra Lee, Delzell, Elizabeth, Dost, Frank, Greenberg, Raymond S., Hatch, Maureen, Hodgson, Ernest, Ibrahim, Michel A., Lamb, James, Lavy, Terry, Mandel, Jack, Monson, Richard, Robson, Mark, Shore, Roy, & Graham, John D.; “The Federal Government’s Agricultural Health Study: A Critical Review with Suggested Improvements;” Human and Ecological Risk Assessment: An International Journal, 2000, 6(1), 47-71; DOI: 10.1080/10807030091124446.

ABSTRACT:

The Agricultural Health Study (AHS) has approximately 90,000 pesticide applicators and their spouses enrolled in a number of studies to determine whether exposures to specific pesticides are associated with various cancers and other adverse health outcomes. Although the AHS was intended to be an integrated program of studies, some significant difficulties have emerged. In this report, we examine the design of the AHS, identify important program strengths and flaws, suggest various improvements in the program, and recommend ancillary studies that could be undertaken to strengthen the AHS.

Overall, the AHS is collecting a large amount of information on potential determinants of health status among farmers and farm families. A promising feature of the AHS is the prospective cohort study of cancers among farmers in which the research design determines exposures prior to the diagnosis of disease. More effort needs to be devoted to reducing selection bias and information bias. Success of the cohort study will depend in part on follow-up surveys of the cohort to determine how exposures and disease states change as the cohort ages. The cross-sectional and case-control studies planned in the AHS are less promising because they will be subject to some of the same criticisms, such as potentially biased and imprecise exposure assessment, that have characterized the existing literature in this field.

Important limitations of the AHS include low and variable rates of subject response to administered surveys, concerns about the validity of some self-reported non-cancer health outcomes, limited understanding of the reliability and validity of self-reporting of chemical use, an insufficient program of biological monitoring to validate the exposure surrogates employed in the AHS questionnaires, possible confounding by unmeasured, nonchemical risk factors for disease, and the absence of detailed plans for data analysis and interpretation that include explicit, a priori hypotheses. Although the AHS is already well underway, most of these limitations can be addressed by the investigators if adequate resources are made available. If these limitations are not addressed, the large amounts of data generated in the AHS will be difficult to interpret. If the exposure and health data can be validated, the scientific value of the AHS should be substantial and enduring.

A variety of research recommendations are made to strengthen the AHS. They include reliability and validity studies of farmer reporting of chemical use, biological monitoring studies of farmers and members of farm families, and validity studies of positive and negative self-reports of disease status. Both industry and government should consider expanded research programs to strengthen the AHS.

FULL TEXT


Parron et al, 2011

Parron, T., Requena, M., Hernandez, A. F., & Alarcon, R.; “Association between environmental exposure to pesticides and neurodegenerative diseases;” Toxicology and Applied Pharmacology, 2011, 256(3), 379-385; DOI: 10.1016/j.taap.2011.05.006.

ABSTRACT:

Preliminary studies have shown associations between chronic pesticide exposure in occupational settings and neurological disorders. However, data on the effects of long-term non-occupational exposures are too sparse to allow any conclusions. This study examines the influence of environmental pesticide exposure on a number of neuropsychiatric conditions and discusses their underlying pathologic mechanisms. An ecological study was conducted using averaged prevalence rates of Alzheimer’s disease, Parkinson’s disease, multiple sclerosis, cerebral degeneration, polyneuropathies, affective psychosis and suicide attempts in selected Andalusian health districts categorized into areas of high and low environmental pesticide exposure based on the number of hectares devoted to intensive agriculture and pesticide sales per capita. A total of 17,429 cases were collected from computerized hospital records (minimum dataset) between 1998 and 2005. Prevalence rates and the risk of having Alzheimer’s disease, Parkinson’s disease, multiple sclerosis and suicide were significantly higher in districts with greater pesticide use as compared to those with lower pesticide use. The multivariate analyses showed that the population living in areas with high pesticide use had an increased risk for Alzheimer’s disease and suicide attempts and that males living in these areas had increased risks for polyneuropathies, affective disorders and suicide attempts. In conclusion, this study supports and extends previous findings and provides an indication that environmental exposure to pesticides may affect the human health by increasing the incidence of certain neurological disorders at the level of the general population. FULL TEXT


Curl et al., 2020

Curl, C. L., Spivak, M., Phinney, R., & Montrose, L.; “Synthetic Pesticides and Health in Vulnerable Populations: Agricultural Workers;” Current Environmental Health Reports, 2020, 7(1), 13-29; DOI: 10.1007/s40572-020-00266-5.

ABSTRACT:

PURPOSE OF REVIEW: This review aims to summarize epidemiological literature published between May 15, 2018, and May 14, 2019, that examines the relationship between exposure to synthetic pesticides and health of agricultural workers.

RECENT FINDINGS: Current research suggests that exposure to synthetic pesticides may be associated with adverse health outcomes. Agricultural workers represent a potentially vulnerable population, due to a combination of unique social and cultural risk factors as well as exposure to hazards inherent in agricultural work. Pesticide exposure among agricultural workers has been linked to certain cancers, DNA damage, oxidative stress, neurological disorders, and respiratory, metabolic, and thyroid effects.

SUMMARY: This review describes literature suggesting that agricultural workers exposed to synthetic pesticides are at an increased risk of certain cancers and neurological disorders. Recent research on respiratory effects is sparse, and more research is warranted regarding DNA damage, oxidative stress, metabolic outcomes, and thyroid effects. FULL TEXT