Pesticide Exposure - HH-RA.org

Liu adn Schelar, 2012

Liu, J., & Schelar, E.; “Pesticide exposure and child neurodevelopment: summary and implications;” Workplace Health and Safety, 2012, 60(5), 235-242; quiz 243; DOI: 10.3928/21650799-20120426-73

ABSTRACT:

Widely used around the world, pesticides play an important role in protecting health, crops, and property. However, pesticides may also have detrimental effects on human health, with young children among the particularly vulnerable. Recent research suggests that even low levels of pesticide exposure can affect young children’s neurological and behavioral development. Evidence shows a link between pesticides and neonatal reflexes, psychomotor and mental development, and attention-deficit hyperactivity disorder. Implications include a need for improved risk assessment and health histories by clinicians, greater education at all levels, more common use of integrated pest management, and continued policy and regulatory strategies to mitigate the effects of and the need for pesticides. FULL TEXT

Rappazzo et al., 2018

Rappazzo, K. M., Warren, J. L., Davalos, A. D., Meyer, R. E., Sanders, A. P., Brownstein, N. C., & Luben, T. J.; “Maternal residential exposure to specific agricultural pesticide active ingredients and birth defects in a 2003-2005 North Carolina birth cohort;” Birth Defects Research, 2018; DOI: 10.1002/bdr2.1448.

ABSTRACT:

BACKGROUND: Previously we observed elevated odds ratios (ORs) for total pesticide exposure and 10 birth defects: three congenital heart defects and structural defects affecting the gastrointestinal, genitourinary and musculoskeletal systems. This analysis examines association of those defects with exposure to seven commonly applied pesticide active ingredients.

METHODS: Cases were live-born singleton infants from the North Carolina Birth Defects Monitoring Program linked to birth records for 2003-2005; noncases served as controls (total n = 304,906). Pesticide active ingredient exposure was assigned using a previously constructed metric based on crops within 500 m of residence, dates of pregnancy, and likely chemical application dates for each pesticide-crop combination. ORs (95% CI) were estimated with logistic regression for categories of exposure compared to unexposed. Models were adjusted for maternal race/ethnicity, age at delivery, education, marital status, and smoking status.

RESULTS: Associations varied by birth defect and pesticide combinations. For example, hypospadias was positively associated with exposures to 2,4-D (OR50th to <90th percentile : 1.39 [1.18, 1.64]), mepiquat (OR50th to <90th percentile : 1.10 [0.90, 1.34]), paraquat (OR50th to <90th : 1.14 [0.93, 1.39]), and pendimethalin (OR50th to <90th : 1.21 [1.01, 1.44]), but not S-metolachlor (OR50th to <90th : 1.00 [0.81, 1.22]). Whereas atrial septal defects were positively associated with higher levels of exposure to glyphosate, cyhalothrin, S-metolachlor, mepiquat, and pendimethalin (ORs ranged from 1.22 to 1.35 for 50th to <90th exposures, and 1.72 to 2.09 for >90th exposures); associations with paraquat were null or inconsistent (OR 50th to <90th: 1.05 (0.87, 1.27).

CONCLUSION: Our results suggest differing patterns of association for birth defects with residential exposure to seven pesticide active ingredients in North Carolina.

Rappazzo et al., 2018

Rappazzo, K. M., Warren, J. L., Davalos, A. D., Meyer, R. E., Sanders, A. P., Brownstein, N. C., & Luben, T. J.; “Maternal residential exposure to specific agricultural pesticide active ingredients and birth defects in a 2003-2005 North Carolina birth cohort;” Birth Defects Research, 2018; DOI: 10.1002/bdr2.1448.

ABSTRACT:

BACKGROUND: Previously we observed elevated odds ratios (ORs) for total pesticide exposure and 10 birth defects: three congenital heart defects and structural defects affecting the gastrointestinal, genitourinary and musculoskeletal systems. This analysis examines association of those defects with exposure to seven commonly applied pesticide active ingredients.

METHODS: Cases were live-born singleton infants from the North Carolina Birth Defects Monitoring Program linked to birth records for 2003-2005; noncases served as controls (total n = 304,906). Pesticide active ingredient exposure was assigned using a previously constructed metric based on crops within 500 m of residence, dates of pregnancy, and likely chemical application dates for each pesticide-crop combination. ORs (95% CI) were estimated with logistic regression for categories of exposure compared to unexposed. Models were adjusted for maternal race/ethnicity, age at delivery, education, marital status, and smoking status.

RESULTS: Associations varied by birth defect and pesticide combinations. For example, hypospadias was positively associated with exposures to 2,4-D (OR50th to <90th percentile : 1.39 [1.18, 1.64]), mepiquat (OR50th to <90th percentile : 1.10 [0.90, 1.34]), paraquat (OR50th to <90th : 1.14 [0.93, 1.39]), and pendimethalin (OR50th to <90th : 1.21 [1.01, 1.44]), but not S-metolachlor (OR50th to <90th : 1.00 [0.81, 1.22]). Whereas atrial septal defects were positively associated with higher levels of exposure to glyphosate, cyhalothrin, S-metolachlor, mepiquat, and pendimethalin (ORs ranged from 1.22 to 1.35 for 50th to <90th exposures, and 1.72 to 2.09 for >90th exposures); associations with paraquat were null or inconsistent (OR 50th to <90th: 1.05 (0.87, 1.27).

CONCLUSION: Our results suggest differing patterns of association for birth defects with residential exposure to seven pesticide active ingredients in North Carolina.

Aylward et al., 2010

Aylward, Lesa L., Morgan, Marsha K., Arbuckle, Tye E., Barr, Dana B., Burns, Carol J., Alexander, Bruce H., & Hays, Sean M.; “Biomonitoring data for 2,4-dichlorophenoxyacetic acid in the United States and Canada: Interpretation in a public health risk assessment context using biomonitoring equivalents;” Environmental Health Perspectives, 2010, 118, 177-181; DOI: 10.1289/ehp.0900970.

ABSTRACT:

BACKGROUND: Several extensive studies of exposure to 2,4-dichlorophenoxyacetic acid (2,4-D) using urinary concentrations in samples from the general population, farm applicators, and farm family members are now available. Reference doses (RfDs) exist for 2,4-D, and Biomonitoring Equivalents (BEs; concentrations in urine or plasma that are consistent with those RfDs) for 2,4-D have recently been derived and published.

OBJECTIVE: We reviewed the available biomonitoring data for 2,4-D from the United States and Canada and compared them with BE values to draw conclusions regarding the margin of safety for 2,4-D exposures within each population group.

DATA SOURCES: Data on urinary 2,4-D excretion in general and target populations from recent published studies are tabulated and the derivation of BE values for 2,4-D summarized.

DATA SYNTHESIS: The biomonitoring data indicate margins of safety (ratio of BE value to biomarker concentration) of approximately 200 at the central tendency and 50 at the extremes in the general population. Median exposures for applicators and their family members during periods of use appear to be well within acute exposure guidance values.

CONCLUSIONS: Biomonitoring data from these studies indicate that current exposures to 2,4-D are below applicable exposure guidance values. This review demonstrates the value of biomonitoring data in assessing population exposures in the context of existing risk assessments using the BE approach. Risk managers can use this approach to integrate the available biomonitoring data into an overall assessment of current risk management practices for 2,4-D.

FULL TEXT

Hart et al., 2005

Hart, L. G., Larson, E. H., & Lishner, D. M.; “Rural definitions for health policy and research;” American Journal of Public Health, 2005, 95(7), 1149-1155; DOI: 10.2105/AJPH.2004.042432.

ABSTRACT:

The term “rural” suggests many things to many people, such as agricultural landscapes, isolation, small towns, and low population density. However, defining “rural” for health policy and research purposes requires researchers and policy analysts to specify which aspects of rurality are most relevant to the topic at hand and then select an appropriate definition. Rural and urban taxonomies often do not discuss important demographic, cultural, and economic differences across rural places-differences that have major implications for policy and research. Factors such as geographic scale and region also must be considered. Several useful rural taxonomies are discussed and compared in this article. Careful attention to the definition of “rural” is required for effectively targeting policy and research aimed at improving the health of rural Americans. FULL TEXT

Jugulam et al., 2018

Jugulam, Mithila, Varanasi, Aruna K., Varanasi, Vijaya K., & Prasad, P. V. V. (2018). Climate Change Influence on Herbicide Efficacy and Weed Management. In S. S. Yadav, R. J. Redden, J. L. Hatfield, A. W. Ebert, & D. Hunter (Eds.), Food Security and Climate Change (First ed., pp. 433-448): John Wiley & Sons Ltd.

INTRODUCTION:

Climate change refers to a change in the climate system that persists for long periods of time, irrespective of the cause. Since the industrial revolution, climate change has been more often associated with a rise in the concentration of greenhouse gases such as carbon dioxide (CO2), methane, nitrous oxide, and halocarbons. The concentration of atmospheric CO2 is steadily rising and is expected to reach ∼1000 μmolmol−1 by the year 2100 with a simultaneous increase of 2–4∘C in the earth’s annual surface temperature (IPCC, 2013). Human activities such as the burning of fossil fuels and deforestation have contributed to a large extent to the emission of greenhouse gases (IPCC 2013, MacCracken et al., 1990). Continued emission of these gases may lead to unprecedented climate changes involving high global temperatures, erratic precipitation and wind patterns, and weather extremities such as droughts, floods, and severe storms (Tubiello et al., 2007; Robinson and Gross, 2010; Gillett et al., 2011; Coumou and Rahmstorf, 2012). Such extreme weather events and rapid climatic changes will have major impacts on the stability of ecosystems; consequently influencing plant life and agriculture (Dukes and Mooney, 1999). Crop production and agronomic practices involving weed management and pest control may be severely affected by these altered abiotic conditions primarily caused by changes in climate and climate variability (Dukes et al., 2009, Singer et al., 2013). Warmer and wetter climates not only affect weed growth but also change chemical properties of certain herbicides; thereby altering their performance on weeds and their control (Poorter and Navas, 2003; Dukes et al., 2009). Determining the response of weeds and herbicides to increased CO2 levels and associated changes in other climate variables is critical to optimize weed management strategies in the context of climate change. This chapter provides an overview of the impacts of climate change factors on weed growth and herbicide efficacy, particularly focusing on the impacts of climate factors on the underlying physiological mechanisms that determine herbicide performance. FULL TEXT

Jugulam et al., 2018

Jugulam, Mithila, Varanasi, Aruna K., Varanasi, Vijaya K., & Prasad, P. V. V. (2018). Climate Change Influence on Herbicide Efficacy and Weed Management. In S. S. Yadav, R. J. Redden, J. L. Hatfield, A. W. Ebert, & D. Hunter (Eds.), Food Security and Climate Change (First ed., pp. 433-448): John Wiley & Sons Ltd.

INTRODUCTION:

Climate change refers to a change in the climate system that persists for long periods of time, irrespective of the cause. Since the industrial revolution, climate change has been more often associated with a rise in the concentration of greenhouse gases such as carbon dioxide (CO2), methane, nitrous oxide, and halocarbons. The concentration of atmospheric CO2 is steadily rising and is expected to reach ∼1000 μmolmol−1 by the year 2100 with a simultaneous increase of 2–4∘C in the earth’s annual surface temperature (IPCC, 2013). Human activities such as the burning of fossil fuels and deforestation have contributed to a large extent to the emission of greenhouse gases (IPCC 2013, MacCracken et al., 1990). Continued emission of these gases may lead to unprecedented climate changes involving high global temperatures, erratic precipitation and wind patterns, and weather extremities such as droughts, floods, and severe storms (Tubiello et al., 2007; Robinson and Gross, 2010; Gillett et al., 2011; Coumou and Rahmstorf, 2012). Such extreme weather events and rapid climatic changes will have major impacts on the stability of ecosystems; consequently influencing plant life and agriculture (Dukes and Mooney, 1999). Crop production and agronomic practices involving weed management and pest control may be severely affected by these altered abiotic conditions primarily caused by changes in climate and climate variability (Dukes et al., 2009, Singer et al., 2013). Warmer and wetter climates not only affect weed growth but also change chemical properties of certain herbicides; thereby altering their performance on weeds and their control (Poorter and Navas, 2003; Dukes et al., 2009). Determining the response of weeds and herbicides to increased CO2 levels and associated changes in other climate variables is critical to optimize weed management strategies in the context of climate change. This chapter provides an overview of the impacts of climate change factors on weed growth and herbicide efficacy, particularly focusing on the impacts of climate factors on the underlying physiological mechanisms that determine herbicide performance. FULL TEXT

Shealy et al., 1996

Shealy, Dana B., Bonin, Michael A., Wooten, Joe V., Ashley, David L., Needham, Larry L., & Bond, Andrew E.; “Application of an improved method for the analysis of pesticides and their metabolites in the urine of farmer applicators and their families;” Environment International, 1996, 22(6), 661-675; DOI: 10.1016/s0160-4120(96)00058-x.

ABSTRACT:

As the annual use of pesticides in the United States has escalated, public health agencies have become increasingly concerned about chronic pesticide exposure. However, without reliable, accurate analytical methods for biological monitoring, low-level chronic exposures are often difficult to assess. A method for measuring simultaneously the urinary residues of as many as 20 pesticides has been significantly improved. The method uses a sample preparation which includes enzyme digestion, extraction, and chemical derivatization of the analytes. The derivatized analytes are measured by using gas chromatography coupled with isotope-dilution tandem mass spectrometry. The limits of detection of the modified method are in the high pg/L – low μg/L range, and the average coefficient of variation (CV) of the method was below 20% for most analytes, with approximately 100% accuracy in quantification. This method was used to measure the internal doses of pesticides among selected farmer applicators and their families. Definite exposure and elimination patterns (i.e., an increase in urinary analyte levels following application and then a gradual decrease to background levels) were observed among the farmer applicators and many of the family members whose crops were treated with carbaryl, dicamba, and 2,4-D esters and amines. Although the spouses of farm workers sometimes exhibited the same elimination pattern, the levels of the targeted pesticides or metabolites found in their urine were not outside the ranges found in the general U.S. population (reference range). The farmer applicators who applied the pesticides and some of their children appeared to have higher pesticide or metabolite levels in their urine than those found in the general U.S. population, but their levels were generally comparable to or lower than reported levels in other occupationally exposed individuals. These results, however, were obtained from a nonrandom sampling of farm residents specifically targeted to particular exposures who may have altered their practices because they were being observed; therefore, further study is required to determine if these results are representative of pesticide levels among residents on all farms where these pesticides are applied using the same application techniques. Using this method to measure exposure in a small nonrandom farm population allowed differentiation between overt and background exposure. In addition, the important role of reference-range information in distinguishing between various levels of environmental exposure was reaffirmed. FULL TEXT

Harris et al., 2010

Harris, S. A., Villeneuve, P. J., Crawley, C. D., Mays, J. E., Yeary, R. A., Hurto, K. A., & Meeker, J. D.; “National study of exposure to pesticides among professional applicators: an investigation based on urinary biomarkers;” Journal of Agricultural and Food Chemistry, 2010, 58(18), 10253-10261; DOI: 10.1021/jf101209g.

ABSTRACT:

Epidemiologic studies of pesticides have been subject to important biases arising from exposure misclassification. Although turf applicators are exposed to a variety of pesticides, these exposures have not been well characterized. This paper describes a repeated measures study of 135 TruGreen applicators over three spraying seasons via the collection of 1028 urine samples. These applicators were employed in six cities across the United States. Twenty-four-hour estimates (mug) were calculated for the parent compounds 2,4-D, MCPA, mecoprop, dicamba, and imidacloprid and for the insecticide metabolites MPA and 6-CNA. Descriptive statistics were used to characterize the urinary levels of these pesticides, whereas mixed models were applied to describe the variance apportionment with respect to city, season, individual, and day of sampling. The contributions to the overall variance explained by each of these factors varied considerably by the type of pesticide. The implications for characterizing exposures in these workers within the context of a cohort study are discussed. FULL TEXT

Delcour et al., 2015

Delcour, Ilse, Spanoghe, Pieter, & Uyttendaele, Mieke; “Literature review: Impact of climate change on pesticide use;” Food Research International, 2015, 68, 7-15; DOI: 10.1016/j.foodres.2014.09.030.

ABSTRACT:

Agricultural yields strongly depend on crop protection measures. The main purpose of pesticide use is to increase food security, with a secondary goal being increased standard of living. In view of a changing climate, not only crop yields but also pesticide use is expected to be affected. Therefore, an analysis of the detailed effect of changing climatic variables on pesticide use is conducted. Not only effects on cultivated crops, occurring pests and pesticide efficiency are considered but also implications for technological development, regulations and the economic situation are included as all of these aspects can influence pesticide use. The objective of this review is to gain insights into the specific effect of climate change on the consumer exposure caused by pesticide residues on crops. In terms of climate change, temperature increase and changes in precipitation patterns are the main pest and pathogen infection determinants. An increased pesticide use is expected in form of higher amounts, doses, frequencies and different varieties or types of products applied. Climate change will reduce environmental concentrations of pesticides due to a combination of increased volatilization and accelerated degradation, both strongly affected by a high moisture content, elevated temperatures and direct exposure to sunlight. Pesticide dissipation seems also to be benefitted by higher amounts of precipitation. To overcome this, pesticide use might be changed. An adapted pesticide use will finally impact consumer exposure at the end of the food chain. FULL TEXT

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