Bibliography Tag: epidemiological studies

Bibliography Index

Malagoli et al., 2016

Malagoli, C., Costanzini, S., Heck, J. E., Malavolti, M., De Girolamo, G., Oleari, P., Palazzi, G., Teggi, S., & Vinceti, M.; “Passive exposure to agricultural pesticides and risk of childhood leukemia in an Italian community;” International Journal of Hygiene and Environmental Health, 2016, 219(8), 742-748; DOI: 10.1016/j.ijheh.2016.09.015.

ABSTRACT:

BACKGROUND: Exposure to pesticides has been suggested as a risk factor for childhood leukemia, but definitive evidence on this relation and the specific pesticides involved is still not clear.

OBJECTIVE: We carried out a population-based case-control study in a Northern Italy community to assess the possible relation between passive exposure to agricultural pesticides and risk of acute childhood leukemia.

METHODS: We assessed passive pesticide exposure of 111 childhood leukemia cases and 444 matched controls by determining density and type of agricultural land use within a 100-m radius buffer around children’s homes. We focused on four common crop types, arable, orchard, vineyard and vegetable, characterized by the use of specific pesticides that are potentially involved in childhood induced leukemia. The use of these pesticides was validated within the present study. We computed the odds ratios (OR) of the disease and their 95% confidence intervals (CI) according to type and density of crops around the children’s homes, also taking into account traffic pollution and high-voltage power line magnetic field exposure.

RESULTS: Childhood leukemia risk did not increase in relation with any of the crop types with the exception of arable crops, characterized by the use of 2.4-D, MCPA, glyphosate, dicamba, triazine and cypermethrin. The very few children (n=11) residing close to arable crops had an OR for childhood leukemia of 2.04 (95% CI 0.50-8.35), and such excess risk was further enhanced among children aged <5 years.

CONCLUSIONS: Despite the null association with most crop types and the statistical imprecision of the estimates, the increased leukemia risk among children residing close to arable crops indicates the need to further investigate the involvement in disease etiology of passive exposure to herbicides and pyrethroids, though such exposure is unlikely to play a role in the vast majority of cases. FULL TEXT

 

Burns and Swaen, 2012

Burns, C. J., & Swaen, G. M.; “Review of 2,4-dichlorophenoxyacetic acid (2,4-D) biomonitoring and epidemiology;” Critical Reviews in Toxicology, 2012, 42(9), 768-786; DOI: 10.3109/10408444.2012.710576.

ABSTRACT:

A qualitative review of the epidemiological literature on the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) and health after 2001 is presented. In order to compare the exposure of the general population, bystanders and occupational groups, their urinary levels were also reviewed. In the general population, 2,4-D exposure is at or near the level of detection (LOD). Among individuals with indirect exposure, i.e. bystanders, the urinary 2,4-D levels were also very low except in individuals with opportunity for direct contact with the herbicide. Occupational exposure, where exposure was highest, was positively correlated with behaviors related to the mixing, loading and applying process and use of personal protection. Information from biomonitoring studies increases our understanding of the validity of the exposure estimates used in epidemiology studies. The 2,4-D epidemiology literature after 2001 is broad and includes studies of cancer, reproductive toxicity, genotoxicity, and neurotoxicity. In general, a few publications have reported statistically significant associations. However, most lack precision and the results are not replicated in other independent studies. In the context of biomonitoring, the epidemiology data give no convincing or consistent evidence for any chronic adverse effect of 2,4-D in humans. FULL TEXT

Alavanja et al., 2004

Alavanja, M. C., Hoppin, J. A., & Kamel, F.; “Health effects of chronic pesticide exposure: cancer and neurotoxicity;” Annual review of public health, 2004, 25, 155-197; DOI: 10.1146/annurev.publhealth.25.101802.123020.

ABSTRACT:

Pesticides are widely used in agricultural and other settings, resulting in continuing human exposure. Epidemiologic studies indicate that, despite premarket animal testing, current exposures are associated with risks to human health. In this review, we describe the routes of pesticide exposures occurring today, and summarize and evaluate the epidemiologic studies of pesticide-related carcinogenicity and neurotoxicity in adults. Better understanding of the patterns of exposure, the underlying variability within the human population, and the links between the animal toxicology data and human health effects will improve the evaluation of the risks to human health posed by pesticides. Improving epidemiology studies and integrating this information with toxicology data will allow the human health risks of pesticide exposure to be more accurately judged by public health policy makers. FULL TEXT

Blair et al., 1985

Blair, A., Malker, H., Cantor, K. P., Burmeister, L., & Wiklund, K.; “Cancer among farmers. A review;” Scandinavian Journal of Work, Environment, & Health, 1985, 11(6), 397-407; DOI: 10.5271/sjweh.2208.

ABSTRACT:

During the performance of routine tasks farmers may come in contact with a variety of substances, including pesticides, solvents, oils and fuels, dusts, paints, welding fumes, zoonotic viruses, microbes, and fungi. Because some of these substances are known or suspected carcinogens, the epidemiologic literature regarding cancer risks concerning farmers has been reviewed. Farmers had consistent deficits for cancers of the colon, rectum, liver, and nose. The deficits for cancer of the lung and bladder were particularly striking, presumably due to less frequent use of tobacco among farmers than among people in many other occupational groups. Malignancies frequently showing excesses among farmers included Hodgkin’s disease, leukemia, non-Hodgkin’s lymphoma, multiple myeloma, and cancers of the lip, stomach, prostate, skin (nonmelanotic), brain, and connective tissues. The etiologic factors that may contribute to these excesses in the agricultural environment have not been identified. Detailed, analytic epidemiologic studies that incorporate environmental and biochemical monitoring are needed to clarify these associations. FULL TEXT

Blair and Zahm, 1993

Blair, A., & Zahm, S. H.; “Patterns of pesticide use among farmers: implications for epidemiologic research;” Epidemiology, 1993, 4(1), 55-62; DOI: 10.1097/00001648-199301000-00011.

ABSTRACT:

Epidemiologic studies of farmers have linked pesticides with certain cancers. Information on exposures from many of these studies was obtained by interview of farmers or their next-of-kin. The reliability and validity of data on pesticide use obtained by recall, often years after the event, have been questioned. Pesticide use, however, is an integral component in most agricultural operations, and the farmers’ knowledge and recall of chemicals used may be better than for many other occupations. Contrary to general belief, many farmers typically use only a few pesticides during their lifetimes and make only a few applications per year. Data from U.S. Department of Agriculture surveys indicate that herbicides are applied to wheat, corn, soybeans, and cotton and that application of insecticides to corn averages two or fewer times per year. In epidemiologic studies at the National Cancer Institute, the proportion of farmers ever reporting lifetime use of five or more different chemicals was 7% for insecticides and 20% for herbicides. Surrogate respondents have often been used in epidemiologic studies of cancer; they are able to recall pesticide use with less detail than the farmers themselves. The pesticides reported by surrogates were the same as reported by subjects themselves, but with less frequency. Comparison of reporting by cases and controls provided no evidence of case-response (differential) bias; thus, inaccurate recall of pesticide use by subjects or surrogates would tend to diminish risk estimates and dilute exposure-response gradients. FULL TEXT

Blair et al., 1992

Blair, A., Zahm, S. H., Pearce, N. E., Heineman, E. F., & Fraumeni, J. F., Jr.; “Clues to cancer etiology from studies of farmers;” Scandinavian Journal of Work, Environment, & Health, 1992, 18(4), 209-215; DOI: 10.5271/sjweh.1578.

ABSTRACT:

This article summarizes cancer risks among farmers to clarify the magnitude of the problem and to suggest directions for future research. Significant excesses occurred for Hodgkin’s disease, multiple myeloma, leukemia, skin melanomas, and cancers of the lip, stomach, and prostate. Nonsignificant increases in risk were also noted for non-Hodgkin’s lymphoma and cancers of connective tissue and brain. These excesses occurred against a background of substantial deficits among farmers for total mortality and mortality from many specific diseases. The tumors vary in frequency, histology, and prognosis and do not fall into any obvious grouping. Two commonalities may be important. Several of the tumors excessive among farmers appear to be rising in the general population and are excessive among patients with naturally occurring or medically induced immunodeficiencies. Therefore epidemiologic studies on specific exposures among farmers may help explain the rising trend of certain cancers in developed countries and provide clues to mechanisms of action for environmental carcinogens. FULL TEXT

 

Rydz et al., 2020

Rydz, C. E., Larsen, K., & Peters, C. E.; “Estimating Exposure to Three Commonly Used, Potentially Carcinogenic Pesticides (Chlorolathonil, 2,4-D, and Glyphosate) Among Agricultural Workers in Canada;” Annals of Work Exposures and Health, 2020; DOI: 10.1093/annweh/wxaa109.

ABSTRACT:

OBJECTIVES: Certain pesticides have been associated with adverse health outcomes including cancer and reproductive harms. However, little is known about the prevalence of occupational pesticide exposure among agricultural workers in Canada. The purpose of this study was to estimate the prevalence and likelihood of occupational exposure to pesticides in Canada’s agricultural industry, using three commonly used, potentially carcinogenic pesticides [chlorothalonil, 2,4-dichlorophenoxyacetic acid (2,4-D), and glyphosate] as an example.

METHODS: Estimates were calculated using the Canadian Census of Population and the Census of Agriculture. The number of workers and the proportion of farms applying ‘herbicides’ or ‘fungicides’ by farm type was estimated using survey data from the Census of Agriculture. These values were multiplied to yield the potential number of workers at risk of exposure. Likelihood of exposure (i.e. exposed, probably exposed, and possibly exposed) was then qualitatively assigned using information on crop type, primary expected tasks, crop production practices, and residue transfer data. Additional agricultural workers who are at risk of exposure but not captured by the Census of Agriculture were identified using the 2016 Census of Population.

RESULTS: An estimated range of 37 700-55 800 workers (11-13% of agricultural workers) were exposed to glyphosate in Canada while 30 800-43 600 workers (9-11%) and 9000-14 100 (2.9-3.2%) were exposed to 2,4-D and chlorothalonil, respectively. Approximately 70-75% of workers at risk of exposure were considered probably or possibly exposed to any of the pesticides. Glyphosate exposure was most common among workers in oilseed (29% of oilseed farm workers exposed) and dry pea/bean farms (28%), along with those providing support activities for farms (31%). 2,4-D exposure was most common in corn (28%), other grain (28%), and soybean farms (27%), while chlorothalonil exposure was more likely among greenhouse, nursery, and floriculture workers (42%), workers on farms (28%, for occupations not captured by the Census of Agriculture, specifically), and those providing support activities for farms (20%). Regional variations broadly reflected differences in farm types by province.

CONCLUSIONS: This study estimated the prevalence of occupational exposure to three pesticides in Canada. Seasonal and temporary agricultural workers, which were captured by the Census of Agriculture, contributed to many additionally exposed workers. A large percent of the workers who were considered at risk of exposure were considered probably or possibly exposed, indicating a need for enhanced data collection and availability on pesticide use data in Canada. The study’s methods can be applied to estimate workers’ exposures to other pesticides within the agricultural industry.

Alavanja et al., 2004

Alavanja, M. C., Dosemeci, M., Samanic, C., Lubin, J., Lynch, C. F., Knott, C., Barker, J., Hoppin, J. A., Sandler, D. P., Coble, J., Thomas, K., & Blair, A.; “Pesticides and lung cancer risk in the agricultural health study cohort;” American Journal of Epidemiology, 2004, 160(9), 876-885; DOI: 10.1093/aje/kwh290.

ABSTRACT:

The authors examined the relation between 50 widely used agricultural pesticides and lung cancer incidence in the Agricultural Health Study, a prospective cohort study of 57,284 pesticide applicators and 32,333 spouses of farmer applicators with no prior history of lung cancer. Self-administered questionnaires were completed at enrollment (1993-1997). Cancer incidence was determined through population-based cancer registries from enrollment through December 31, 2001. A lung cancer standardized incidence ratio of 0.44 (95% confidence interval: 0.39, 0.49) was observed overall, due in large part to a low cigarette smoking prevalence. Two widely used herbicides, metolachlor and pendimethalin (for low-exposed groups to four higher exposure categories: odds ratio (OR) = 1.0, 1.6, 1.2, 5.0; p(trend) = 0.0002; and OR = 1.0, 1.6, 2.1, 4.4; p(trend) = 0.003, respectively), and two widely used insecticides, chlorpyrifos and diazinon (OR = 1.0, 1.1, 1.7, 1.9; p(trend) = 0.03; and OR = 1.0, 1.6, 2.7, 3.7; p(trend) = 0.04, respectively), showed some evidence of exposure response for lung cancer. These excesses could not be explained by previously identified lung cancer risk factors. The usage levels in this cohort are considerably higher than those typically experienced by the general population. An excess risk among spouses directly exposed to pesticides could not be evaluated at this time. FULL TEXT

van der Plaat et al., 2018

van der Plaat, Diana A., de Jong, Kim, de Vries, Maaike, van Diemen, Cleo C., Nedeljković, Ivana, Amin, Najaf, Kromhout, Hans, Vermeulen, Roel, Postma, Dirkje S., van Duijn, Cornelia M., Boezen, H. Marike, & Vonk, Judith M.; “Occupational exposure to pesticides is associated with differential DNA methylation;” Occupational and environmental medicine, 2018, 75(6), 427; DOI: 10.1136/oemed-2017-104787.

ABSTRACT:

OBJECTIVES: Occupational pesticide exposure is associated with a wide range of diseases, including lung diseases, but it is largely unknown how pesticides influence airway disease pathogenesis. a potential mechanism might be through epigenetic mechanisms, like Dna methylation. therefore, we assessed associations between occupational exposure to pesticides and genome-wide Dna methylation sites.

METHODS: 1561 subjects of lifelines were included with either no (n=1392), low (n=108) or high (n=61) exposure to any type of pesticides (estimated based on current or last held job). Blood Dna methylation levels were measured using illumina 450K arrays. associations between pesticide exposure and 420 938 methylation sites (cpgs) were assessed using robust linear regression adjusted for appropriate confounders. in addition, we performed genome-wide stratified and interaction analyses by gender, smoking and airway obstruction status, and assessed associations between gene expression and methylation for genome-wide significant cpgs (n=2802).

RESULTS: In total for all analyses, high pesticide exposure was genome-wide significantly (false discovery rate P<0.05) associated with differential Dna methylation of 31 cpgs annotated to 29 genes. twenty of these cpgs were found in subjects with airway obstruction. Several of the identified genes, for example, RYR1, ALLC, PTPRN2, LRRC3B, PAX2 and VTRNA2-1, are genes previously linked to either pesticide exposure or lungrelated diseases. Seven out of 31 cpgs were associated with gene expression levels.

CONCLUSIONS: We show for the first time that occupational exposure to pesticides is genome-wide associated with differential Dna methylation. Further research should reveal whether this differential methylation plays a role in the airway disease pathogenesis induced by pesticides.

FULL TEXT

Christensen et al., 2016

Christensen, C. H., Barry, K. H., Andreotti, G., Alavanja, M. C., Cook, M. B., Kelly, S. P., Burdett, L. A., Yeager, M., Beane Freeman, L. E., Berndt, S. I., & Koutros, S.; “Sex Steroid Hormone Single-Nucleotide Polymorphisms, Pesticide Use, and the Risk of Prostate Cancer: A Nested Case-Control Study within the Agricultural Health Study;” Frontiers in Oncology, 2016, 6, 237; DOI: 10.3389/fonc.2016.00237.

ABSTRACT:

Experimental and epidemiologic investigations suggest that certain pesticides may alter sex steroid hormone synthesis, metabolism or regulation, and the risk of hormone-related cancers. Here, we evaluated whether single-nucleotide polymorphisms (SNPs) involved in hormone homeostasis alter the effect of pesticide exposure on prostate cancer risk. We evaluated pesticide-SNP interactions between 39 pesticides and SNPs with respect to prostate cancer among 776 cases and 1,444 controls nested in the Agricultural Health Study cohort. In these interactions, we included candidate SNPs involved in hormone synthesis, metabolism or regulation (N = 1,100), as well as SNPs associated with circulating sex steroid concentrations, as identified by genome-wide association studies (N = 17). Unconditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Multiplicative SNP-pesticide interactions were calculated using a likelihood ratio test. We translated p-values for interaction into q-values, which reflected the false discovery rate, to account for multiple comparisons. We observed a significant interaction, which was robust to multiple comparison testing, between the herbicide dicamba and rs8192166 in the testosterone metabolizing gene SRD5A1 (p-interaction = 4.0 x 10(-5); q-value = 0.03), such that men with two copies of the wild-type genotype CC had a reduced risk of prostate cancer associated with low use of dicamba (OR = 0.62 95% CI: 0.41, 0.93) and high use of dicamba (OR = 0.44, 95% CI: 0.29, 0.68), compared to those who reported no use of dicamba; in contrast, there was no significant association between dicamba and prostate cancer among those carrying one or two copies of the variant T allele at rs8192166. In addition, interactions between two organophosphate insecticides and SNPs related to estradiol metabolism were observed to result in an increased risk of prostate cancer. While replication is needed, these data suggest both agonistic and antagonistic effects on circulating hormones, due to the combination of exposure to pesticides and genetic susceptibility, may impact prostate cancer risk. FULL TEXT

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