EDC Pesticide Exposure Effects on Detrimental Chronic Health Issues in Migrant Farm Workers

Introduction

The use of pesticides to combat insects that destroy food crops across United States farms have exhibited detrimental health effects on migrant farm workers who are chronically exposed while performing field labor occupation practices. Consequently, lack of or delay of regulatory functions eradicating usage of EDC pesticides such as dichloro-diphenyl-trichloromethane (DDT) or methoxychlor have led to more rapid onset of chronic health complications at younger ages in exposed migrant field workers. The most sensitive reaction amongst a subgroup of the exposed migrant workers to these pesticides are children of pregnant females exposed while in the gestation period of development most significantly in the first trimester where high DNA methylation activity is most apparent making epigenetic alteration effects most at risk to occur. The results of epigenetic alterations often lead to latent health effects that do not phenotypically show as symptoms until later on in an individual’s life. Furthermore, the endocrine disruptor capabilities of pesticides also display negative long term effects on individual migrant worker health in which will be more analyzed in the proceeding section.

Endocrine Disruptor Compounds

The dysregulation of hormone levels can lead to various health complications ranging from precocious puberty, endocrine cancers, and congenital abnormalities. The primary method of how these endocrine disrupting compounds create such a negative impact on cellular processes is diagrammed appropriately in figure 1 where the tactic of mimicry is appropriately displayed.  The sensitivity of babies exposed to EDC’s that cross the placental barrier is heightened during this pregnancy and can result in latent health effects from epigenetic alterations. Many cancer genomic researchers believe the higher prevalence rates of breast cancer and testicular cancer over the past 20 years as reported by the Centers of Disease Control and Prevention is probably linked to the rise of EDC exposures in various products, plastics, and pesticides over the past few decades though a direct cause has not yet been linked (CDC, 2016).  The presence of persistent pesticides in one study conducted on migrant farm workers exposed to EDC pesticides DDT and hexachlorobenzene (HCB) resulted in statistically significant thyroid-disrupting effects on T4 cells of exposed workers (Boas et al., 2012). The thyroid gland is a major indicator and transducer of endocrine system processes.  

Figure 1: The disruption of hormonal signaling results from EDC pesticide exposures (NIOSH, 2016)

Past and Existing Studies Conducted; Validity and Generalizability of Studies

Many previous study examples have helped to link the correlation of EDC pesticide hazardous exposure to endocrine disease onset. For example, one study sampled 6,038 Hispanic female migrant workers exposed to EDC pesticides prior to their regulation in the early 2000’s at farms in Iowa and North Carolina throughout the 1990’s showed significant display of later onset of menopause age which related with most with the amount of time & type of pesticide exposure that occurred over the sample time period (Farr et al., 2006).  Another example was for one cross-sectional study conducted to evaluate the relationship between exposure to selected organochlorine pesticides and age at natural menopause in 219 menopausal women participating in the Hispanic Health and Nutrition Examination Survey in1982-1984. Women with exposure levels in the highest exposure category to the EDC pesticide DDT had an adjusted mean age of menopause on average up too 5.7 years earlier than natural control menopause age of women (Akkina et al., 2004). Finally, a survey conducted in 2001-2002 by the National Health and Nutrition Survey illustrated that thyroid iodine abnormalities in serum samples collected from Hispanic females and males exposed to pesticides during that given time period exhibited abnormalities of the endocrine gland (Jain, 2014). The validity of the past studies differed in their measures however the results do not generalize the ultimate latent effects associated with epigenetic alterations from EDC pesticide exposure. The next study to be presented provides the most validity and is more precise in its target population in the geographic region of Salinas Valley, California.

Figure 2: The results of endocrine disruptors such as the pesticide methoxychlor leads to deleterious health effects in an everlasting loop of steps (Casati et al., 2015)

CHAMACHO Longitudinal Study on Mexican-American Children of Migrant Workers

The Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) cohort study conducted on 612 pregnant migrant workers and their children in California exposed to organophosphate pesticides at the farms they worked at illustrated lower levels of IQ, developmental neurological issues, and higher risk for shortened pregnancies amongst the sample populations studied (Warner et al., 2014). Furthermore, the study associated higher risk of obesity in the children of perinatal exposed migrant pregnant mothers to pesticide exposures studied over the ten-years spanning from 2000 to 2010. The study was conducted in the agriculture hub of Salinas Valley, California a center community for Mexican immigrant workers which were focused on in this study in order to illustrate the multiple generation deleterious effects of DDT, DDE, etc. pesticide use.  The study found issues that illustrate the risk associated with EDC pesticide exposures in farm worker occupations by showing significant patterns of obesity, neurological development issues, and endocrine system development problems in the offspring of the Mexican Migrant mothers. The results of this study help to increase but not distinctively confirm endocrine disruptor pesticides are still in use in many farms across states like California and even they have been eradicated through regulation they tend to persist in the environment creating immeasurable latent health effects on poverty stricken Hispanic migrant workers exposed to these compounds each day in the occupational setting. Furthermore, the necessity for more access to healthcare services must be implemented by regulatory agencies for migrant workers even in they are undocumented since the children that they give birth to while in this country essentially become American citizens deserving of the right to treatments especially for high risk of pesticide poisonings.

Monitoring & Diagnosis of Health Problems Associated with EDC Pesticide Exposure

The monitoring & detection of pesticide related illnesses amongst migrant workers has been undertaken by the National Institute of Occupational Safety and Health (NIOSH) over the past several years. According to data compiled by NIOSH and organized through the Center of Disease Control & Prevention (CDC) an estimate of 10,000 to 20,000 pesticide poisonings occurs each year among the 2 million migrant workers in agricultural farm settings across the United States (CDC, 2015). The monitoring of pesticide regulation is conducted via the SENSOR-Pesticides program utilized in collaboration with NIOSH and the Environmental Protection Agency (EPA). The recurrent findings that link EDC pesticide exposures and endocrine related disorders amongst migrant field workers across farms in agricultural states such as California led to a diagnosis of a problem the pesticides being used. Furthermore, DDT was banned from use almost 50 years ago but still persists in farm occupational setting in contaminated soil for example meaning that proper removal tasking must be conducted by farm proprietors more efficiently prior to exposing workers to possible health damaging effects.

Methods of Law & Implementation for Pesticide Regulation Policies

The methodology that led to the law & implementation of regulation policy for endocrine disrupting compounds such as methoxychlor and organochlorine pesticides was the analysis of developmental defects amongst children of both human sample studies & extrapolated data from animal studies. The EPA has thus been responsible for the banning of many EDC pesticides such as methoxychlor in 2003 and other organochlorine pesticides over the following years; however, the exposure health consequences amongst past generations of migrant workers can be transgenerationally inherited amongst migrant worker children as illustrated in the main study to be analyzed later on in this paper focusing on a longitudinal cohort study on children of Mexican migrant farm workers in California. The problem with the methodology for pesticide regulation policies was the speed in which they were finally initiated into action. People must consider that these pesticides may have already incurred much of their damage even if not readily seen due to the latent (hidden) epigenetic health damage which occurred in chronically exposed field workers and will eventually be passed down to successive generations implicating the scale of public health impact EDC pesticide use has on the hard working and poverty stricken migrant worker populations that help to provide food to our nation. Certain classifications for EDC pesticide chemicals have also been implemented by regulatory agencies in order to discern the type of chemical structures and family groups a given chemical belongs with. For example, persistant pollutant categories of pesticides would help warn farmers of the danger posed by improper removal of the pesticide hazard from soil and crops on their farm commonly the area of work where migrant field laborers will spend long days around.

Prevention and Pesticide Control Focused on 3 E’s of Prevention Area Focus

The EPA has thus been responsible for the banning of methoxychlor as a pesticide in 2003 and other organochlorine pesticides; however, the exposure health consequences amongst past generations of migrant workers can be transgenerationally inherited amongst migrant worker children as illustrated in the aforementioned cohort study in California. The three E’s of preventative area focus in concern with pesticide exposure reduction include the following: education, engineering, and enforcement measures. Education prevention measures through the use of informational pesticide hazard courses as provided in the mostly migrant worker agricultural farming communities across the state of California; thus, the state’s OEHHA department has implemented educational prevention via the easy to access use of pesticide related illness danger online courses, California medical prevention supervision programs, and poison control center free pamphlets concerning pesticide related illness symptoms (OEHHA, 2016). Engineering preventive measures through recommendations of the utilization of alternative means to dangerous pesticide usage has been occurring across many farms in the United States due to the engineering of synthetic chemical alternatives, more use of technological agriculture tools, and analysis of geographic information services utilized by the EPA (CDC, 2016). Enforcement preventive measures through the expansion of occupational health map analysis across multiple states has allowed for better enforcement of regulation of pesticides via the geographic worker information compiled by the council of state & territory epidemiologists (CSTE, 2016). The hiring of more healthcare professionals that can provide access to care for these migrant workers via employee benefit programs could help bring about a reduction of pesticide-related illnesses.

 Future Direction of EDC Pesticide Mitigation and Migrant Worker Future Safety

Research needs are highly prevalent amongst the migrant workers that often find it difficult to access healthcare facilities due to poverty, rural isolation, etc. which leads to a great amount of data that has not been analyzed concerning the possible developmental health effects of the children of exposed migrant workers. The implementation of tighter regulations concerning pesticide use at both the state and federal government levels must be conducted in order to decrease & monitor pesticide exposure levels. The increased exposure of endocrine related issues over the coming years will probably lead to more studies being conducted on how to provide alternative chemicals and effective study analysis. Reconciling pesticide reduction for the same amount of food crop output will be a primary goal for global sustainable crop farming and one study showed increased crop rotation as well as higher levels of worker productivity with high correspondence to low pesticide usage in two major agricultural regions of France proving that possible reductions of expensive pesticide use can help allocate saved funds to promote better health services to migrant workers in the near future (Lechenet et al., 2014).  Furthermore, research and technological progress may present excellent alternative ideas that will help promote both more environmentally and occupationally friendly work settings across farms in America.  Finally, the hiring of more local EPA & OSHA investigative officers will help stymie the abuse of pesticide usage conducted by farm owners where migrant workers are utilized.  The evidence for adverse reproductive outcomes (infertility prevalence, recent testicular & breast cancer rate proliferation, etc.) from exposure to EDC pesticides is strong, and mounting evidence for effects on other endocrine systems, including thyroid, neuroendocrine, obesity and glucose homeostasis have been linked to EDC exposure according to the American Public Health Association (APHA, 2016). Congress formally recognized EDCs as a public health concern in 1996 when it passed the Food Quality Protection Act (FQPA) and amendments to the Safe Drinking Water Act. Thirteen years later, in 2009, the US Environmental Protection Agency (EPA) issued its first test orders for screening of dozens of high-priority pesticides for endocrine disrupting effects (APHA, 2016). Many of these regulatory actions unfortunately have only been sanctioned recently meaning much damage from EDC pesticides in the recent past was still being incurred upon migrant populations of workers across American farms. If continued detrimental health effects keep occurring at high rates in these populations without the help of local officials the consequences of their children being unable to properly develop and possibly make a future as educated American citizens will continue to look bleak as a result of cognitive impairments from pesticide-related exposure.

 EDC Pesticide Effects On Migrant Workers Final Summary & Recommendations

The prevalence of pesticide-related illness amongst migrant workers is an area of deep public health concern and is not properly researched in regards to not only the health effects of current migrant workers but the health effects due to epigenetically inherited health detriments seen in the children of these workers. Monitoring and detection of pesticide related illnesses is currently conducted at a federal level amongst the NIOSH and EPA agencies devoted to reducing the prevalence of banned pesticide usage across the country. However, even with the new wave of bans and regulations concerning EDC pesticide usage the latent effects of future generations of migrant worker children is largely being unconsidered. The mounting evidence of epigenetic alterations concerning the developmental phases of migrant children during crucial early life stages of cognitive development makes the possible widespread endemic of neurological deficits in these children a more realistic possibility. Thus, the implementation of better access to care for these workers and their children is essential to help stymie the health burdens that are a consequence of pesticide exposure. This paper will seek to analyze the possible ways to improve the understanding of disease consequences from pesticide usage at both an epigenetic and physically hazardous level of research analysis. Furthermore, the recommendations of alternatives to the beneficial aspects of pesticide usage will be ascertained through analysis of educational, engineering, and enforcement prevention strategies. The main occupational diseases that will mostly be investigated will be reproductive illnesses or cancers that originate from epigenetic disruption of neuroendocrine genetic mechanisms of reproductive life span regulation in our bodies. In conclusion, the public health ramifications of better understanding how endocrine disrupting compound pesticides such as DDT, methoxychlor, etc. alter the occupational health status of migrant workers in a negative way and how these negative health implications can be passed on to future generations of migrant worker children will help bring more awareness on the necessity to minimize pesticide exposure levels at farms across the United States.

References

Cummings AM (1997). methoxychlor as a model for environmental estrogens. crit rev toxicol 27(4):367-79.

Farr, S. L., Cai, J., Savitz, D. A., Sandler, D. P., Hoppin, J. A., & Cooper, G. S. (2006). Pesticide exposure and timing of menopause: The agricultural health study. American Journal of Epidemiology, 163(8), 731-742.

Fleisch, A. F., Wright, R. O., & Baccarelli, A. A. (2012). Environmental epigenetics: A role in endocrine disease? Journal of Molecular Endocrinology, 49(2), R61-7.

Gore, A. C., Walker, D. M., Zama, A. M., Armenti, A. E., & Uzumcu, M. (2011). Early life exposure to endocrine-disrupting chemicals causes lifelong molecular reprogramming of the hypothalamus and premature reproductive aging. Molecular Endocrinology, 25(12), 2157-2168.

Landrigan, P. (2011). Children's vulnerability to chemicals: A challenge and opportunity to strengthen health and environmental policy. Health Affairs (Millwood, Va.), 30(5), 842; 842-850; 850.

Meeker, J. D. (2012). Exposure to environmental endocrine disruptors and child development. Archives of Pediatrics & Adolescent Medicine, 166(10), 952-958.

CDC Database, (2016). http://www.cdc.gov/niosh/topics/pesticides/overview.html \

OEHHA Website (2016). http://oehha.ca.gov/pesticides/education-and-training

Agay - Shay, K., Martinez, D., Valvi, D., Garcia - Esteban, R., Basagana, X., Robinson, O., . . . Vrijheid, M. (2015). Exposure to endocrine-disrupting chemicals during pregnancy and weight at 7 years of age: A multi-pollutant approach.(research: Children's health)(report). Environmental Health Perspectives, 123(10), 1030.

Akkina, J. E., Reif, J. S., Keefe, T. J., & Bachand, A. M. (2004). Age at natural menopause and exposure to organochlorine pesticides in hispanic women. Journal of Toxicology and Environmental Health, Part A, 67(18), 1407-1422.

Boas, M., Feldt-Rasmussen, U., & Main, K. M. (2012). Thyroid effects of endocrine disrupting chemicals. Molecular and Cellular Endocrinology, 355(2), 240-248.

Casati, L., Sendra, R., Sibilia, V., & Celotti, F. (2015). Endocrine disrupters: The new players able to affect the epigenome. Frontiers in Cell and Developmental Biology, 3

Das, R., Steege, A., Baron, S., Beckman, J., & Harrison, R. (2001). Pesticide-related illness among migrant farm workers in the united states. International Journal of Occupational and Environmental Health, 7(4), 303-312.

De Onis, M., Onyango, A. W., Borghi, E., Siyam, A., Nishida, C., & Siekmann, J. (2007). Development of a WHO growth reference for school-aged children and adolescents/Mise au point d'une reference de croissance pour les enfants d'age scolaire et les adolescents/ elaboracion de valores de referencia de la OMS para el crecimiento de escolares y adolescentes.(research)(author abstract). Bulletin of the World Health Organization, 85(9), 660.

Delvaux, I., Van Cauwenberghe, J., Den Hond, E., Schoeters, G., Govarts, E., Nelen, V., . . . Sioen, I. (2014). Prenatal exposure to environmental contaminants and body composition at age 7–9 years. Environmental Research, 132, 24.

Farr, S. L., Cai, J., Savitz, D. A., Sandler, D. P., Hoppin, J. A., & Cooper, G. S. (2006). Pesticide exposure and timing of menopause: The agricultural health study. American Journal of Epidemiology, 163(8), 731-742. doi:kwj099 [pii]

Han, Y., Peters, D. C., Kissinger, K. V., Goddu, B., Yeon, S. B., Manning, W. J., & Nezafat, R. (2010). Evaluation of papillary muscle function using cardiovascular magnetic resonance imaging in mitral valve prolapse. The American Journal of Cardiology, 106(2), 243.

Jain, R. B. (2014). Association between thyroid function and selected organochlorine pesticides: Data from NHANES 2001–2002. Science of the Total Environment, 466, 706-715.

Warner, M., Wesselink, A., Harley, K. G., Bradman, A., Kogut, K., & Eskenazi, B. (2014). Prenatal exposure to dichlorodiphenyltrichloroethane and obesity at 9 years of age in the CHAMACOS study cohort. American Journal of Epidemiology, 179(11), 1312-1322. doi:10.1093/aje/kwu046 [doi]