18
Aug
Parents’ Exposure to Pesticides Indicative of Childhood Cancer Risk among Offspring
(Beyond Pesticides, August 18, 2022) A study published in Environmental Research suggests occupational (work-related) exposure to pesticides among nonpregnant women and men may increase childhood cancer risk for offspring. Already, studies find low levels of pesticide exposure during pregnancy or childhood cause adverse health effects from metabolic disorders to mental and physical disabilities. However, few assess parental exposure’s impact on childhood disease risk outside critical development periods (e.g., pregnancy). Although medical advancements in disease survival are more prominent nowadays, childhood cancer remains the leading cause of death from disease among children. Furthermore, childhood cancer survivors can suffer from chronic or long-term health complications that may be life-threatening.
The etiology or cause of childhood cancer involves the interaction of multiple components like lifestyle and genetics. However, emerging evidence indicates that environmental contaminants like pesticides (e.g., occupational exposures, air pollution, pesticides, solvents, diet, etc.) play a role in disease etiology. Pesticide contamination is widespread in all ecosystems, and chemical compounds can accumulate in human tissues resulting in chronic health effects. Children are particularly vulnerable to the impacts of pesticide exposure as their developing bodies cannot adequately combat exposure effects. Moreover, several studies demonstrate an association between environmental or occupational pesticide exposure and the risk of childhood cancer. Considering maternal pesticide exposure can have a stronger association with cancer among children than childhood exposure, and newborns can still encounter pesticides, it is important to understand how pesticide accumulation and co-occurrence can increase the risk of latent diseases (e.g., cancers) among vulnerable populations, such as children/infants.
There is a lack of understanding of cancer risk from parental exposure to pesticides via occupation. The study examines whether parents’ exposure to pesticides has an association with childhood cancer development among offspring. The International Classification of Childhood Cancer classifies childhood cancers as leukemias, lymphomas, and central nervous system (CNS) tumors/gliomas.
Using a Swedish register-based case-control study spanning 1960 to 2015, researchers compare juvenile cancer cases from the Cancer Register that are less than 20 years old to healthy (control) children born in the same year. The study investigates parental employment history around the time of the offspring’s birth and evaluates whether there is any exposure to herbicides, insecticides, and fungicides. Logistic regression analyses estimate the risk for cancers, including leukemia, lymphoma, CNS and other solid tumors. Although work-related maternal and paternal exposure to pesticides does not have an increased association with childhood cancer risk overall, exposure indicates a 42 percent higher risk of lymphoma (primarily Hodgkin lymphoma) and a 30 percent increased risk of solid non-CNS tumors in children. Additionally, paternal pesticide exposure can indicate a 15 percent risk for myeloid leukemia. The researchers detect that even low levels of pesticide exposure may lead to a higher risk of childhood cancers.
There is a significant scientific connection between pesticides and cancer as several studies link pesticide use and residues to various cancers, from prevalent forms like breast cancer to rare like kidney cancer nephroblastoma (Wilms’ tumor). Sixty-six percent of all cancers have links to environmental factors, especially in occupations of high chemical use. In addition to the robust links between agricultural practices and pesticide-related illnesses, over 65 percent of commonly used lawn pesticides and 70 percent of commonly used school pesticides have links to cancer. Although general pesticide exposure can increase susceptibility to cancer, prenatal and early-life exposure to environmental toxicants can increase cancer risk. For decades, studies have long demonstrated that childhood and in utero exposure to the U.S. banned insecticide DDT increases the risk of developing breast cancer later in life. Moreover, a 2021 study finds previous maternal exposure to the chemical compound during pregnancy can increase the risk of breast cancer and cardiometabolic disorders (e.g., heart disease, obesity, diabetes) up to three successive generations.
Both current and past-use pesticides and chemical contaminants play a role in similar disease outcomes as several of these chemicals are endocrine disruptors, thus having implications for specific cancer risks (e.g., breast cancer). Even pregnant mothers’ exposure to household cleaners, many of which are pesticides, can increase nephroblastoma (kidney cancer) and brain tumor risk in children. Furthermore, long-term exposure to organophosphate (OP) pesticides increases adverse health and cancer risks, specifically among women. Since DDT and its metabolite DDE residues, current-use pesticides, and other chemical pollutants contaminate the environment, exposure to these chemical mixtures can synergize to increase toxicity and disease effects. Globally, cancer is one of the leading causes of death, with over eight million people succumbing to the disease every year. Notably, the International Agency for Cancer Research (IARC) predicts a 67.4 percent rise in new cancer cases by 2030. Therefore, it is essential to understand how external stimuli—like environmental pollution from pesticides—can drive cancer development to avoid exposure and lessen potential cancer risks.
Although this study does not identify a definitive association between increased risk of all childhood cancer among children and parental occupational exposure to pesticides, maternal occupational exposure indicates a higher risk for specific cancers like lymphoma (i.e., non-Hodgkin lymphoma) and solid non-CNS tumors. Moreover, children of fathers with occupational insecticide exposure have a higher risk of myeloid leukemia. The likely reason for occupational pesticide exposure to indicate potential cancer risk is due to genetic mutation or damage that may occur and passed down to offspring. This alteration makes the offspring more susceptible to other factors that may increase cancer risk. For instance, the risk of developing lymphoma is slightly higher if a close relative (e.g., parent, sibling, offspring) has/had lymphoma or another type of blood cancer. As the rate of chronic diseases like cancer continues to increase in the U.S., and additional studies find these diseases to be pesticide-induced, the public must increase pressure on regulators and lawmakers to enact meaningful measures that eliminate pesticide use and the hazards. The study concludes, “Although these findings merit further investigation, they indicate that parental exposure to pesticides may lead to higher risks of childhood cancer even in settings of low exposure.”
There is a strong consensus among pediatricians that pregnant mothers and young children should avoid pesticide exposure during critical windows of development. However, the general population should follow this advice as the effects of pesticide exposure span every individual. Fortunately, the wide availability of non-pesticidal alternative strategies allows families and agricultural industry workers to apply these methods to promote a safe and healthy environment, especially among chemically vulnerable individuals. For instance, buying, growing, and supporting organic land management can reduce human and environmental contamination from pesticides. Organic agriculture has many health and environmental benefits, which curtail the need for chemical-intensive agricultural practices. Numerous studies find that pesticide metabolite levels in urine significantly decrease when switching to an all-organic diet. For more information on how organic is the right choice for both consumers and the farmworkers that grow our food, see the Beyond Pesticides webpage on Health Benefits of Organic Agriculture.
Both government officials and the public must comprehend the health implications of pesticide use and exposure on humans, especially when pesticides increase chronic disease risk. Beyond Pesticides tracks the most recent news and studies on pesticides through the Daily News Blog and Pesticide-Induced Diseases Database (PIDD). This database supports the need for strategic action to shift away from pesticide dependency. For more information on the adverse effects of pesticides on human health, see PIDD pages on cancer (lymphoma, multiple myeloma), birth/fetal defects, and other diseases. Additionally, since pesticides can have multi-generation impacts on our health, you can learn more about the hazards posed to children’s health through Beyond Pesticide’s Pesticide and You Journal article, “Children and Pesticides Don’t Mix.”
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Source: Environmental Research
