Once again, another study found that being exposed to pesticides has harmful health effects. Of all sorts. A recent study found that pregnant women exposed to certain pesticides increases the risk of a stillbirth. In this case, exposure means living near (less than 1/3 mile) where certain pesticides have been used.
The pesticides linked to increased stillbirths when exposed to in the pre-conception period were: cyfluthrin (a pyrethroid), zeta-cypermethrin (a pyrethroid), pyrethroids as a class, organophosphates as a class, malathion, carbaryl and propamocarb hydrochloride. Exposure in the first trimester of pregnancy to the following pesticides were associated with stillbirths: fenpropathrin (a pyrethroid), permethrin (a pyrethroid), organophosphates as a class, acephate and formetanate hydrochloride.
This means living near a non-organic farm has increased risks to pregnancy and the baby, including stillbirth. Note that some of these are also commonly used residential pesticides, such as pyrethroids (used as insecticides, and especially by mosquito and tick services). We shouldn't be surprised when pesticides applied to kill living things (e.g., insects) also have harmful effects on developing babies (also alive). [Some studies showing harmful effects of pesticides on pregnancy and the developing fetus (baby).]
From Medical Xpress: Pesticide exposure linked to stillbirth risk in new study
Living less than about one-third of a mile from pesticide use prior to conception and during early pregnancy could increase the risk of stillbirths, according to new research led by researchers at the Mel and Enid Zuckerman College of Public Health and Southwest Environmental Health Sciences Center.
Researchers found that during a 90-day pre-conception window and the first trimester of pregnancy, select pesticides, including organophosphates as a class, were associated with stillbirth.
"In this study, some specific ingredients stood out due to their significant associations with stillbirth risk," said first author Melissa Furlong, Ph.D....
To conduct the study, researchers linked Arizona pesticide use records for 27 different pesticides with state birth certificate data that included 1,237,750 births and 2,290 stillbirths from 2006 to 2020.
They found that living within .31 miles (500 meters) of specific pyrethroid, organophosphate or carbamate pesticide applications during a 90-day pre-conception window or the first trimester was associated with an increased risk of stillbirth.
Specifically, the pesticides cyfluthrin, zeta-cypermethrin, organophosphates as a class, malathion, carbaryl and propamocarb hydrochloride were linked to increased stillborn births pre-conception. During the first trimester, fenpropathrin, permethrin, organophosphates as a class, acephate and formetanate hydrochloride were associated with stillbirths.
"Among organophosphates, acephate showed the strongest effect estimates on stillbirth, so that exposure to acephate in the first trimester was associated with a doubling of risk," said co-author Paloma Beamer, Ph.D.,..."Within the pyrethroid class, cyfluthrin exposure during the 90 days prior to conception almost doubled the risk of stillbirth."
Pesticides are chemical substances used to control pests in various settings. They are commonly categorized into different classes, such as organophosphates, pyrethroids and carbamates. The primary route of exposure for most people is through diet, but household use, agricultural drift and occupational exposure are also significant pathways.
Pregnant women may be particularly vulnerable to the adverse effects of pesticide exposure due to physiological changes during pregnancy, such as increased metabolic rate, altered hormone levels and changes in the immune system. The developing fetus may be more susceptible to the toxic effects of pesticides during this period of rapid growth and development.
From Beyond Pesticides: Study Links Pesticide Exposure During Preconception and First Trimester to Stillbirth
“Stillbirth, fetal death, and miscarriage present major physical and psychological health burdens for pregnant women,” the authors state. They continue, “Stillbirth occurs in approximately 4-5 per 1,000 births in developed countries, and up to 3% of births in low and middle income countries.” In finding a correlation between incidence of stillbirth and pesticide exposure, the study highlights additional risks during pregnancy and for those who wish to become pregnant. Those who live near agricultural areas, and specifically female farmworkers, are at a disproportionate risk for these adverse effects.
Previous toxicology studies document the pyrethroid cyfluthrin as altering placental development, which has been hypothesized as a cause of stillbirths and miscarriages. As pesticide exposure causes biological effects on female reproductive organs and hormonal activity, this provides a possible explanation for the correlation of exposure to negative birth outcomes. “Metabolites of permethrin and cypermethrin (which are shared with zeta-cypermethrin) act as endocrine disruptors and interact with cellular estrogen receptors. Such hormonal influences can affect women’s reproductive cycles and cycle lengths, and the overall quality of the uterine environment during pre-implantation,” the authors say. Any effects on uterine and reproductive cells and placental health from pesticide exposure can influence the outcomes of pregnancy.
Impacts on male reproduction from pesticide exposure are also documented. Beyond Pesticides has a long history of highlighting the relationship between reproductive anomalies and toxic pesticides, particularly with endocrine-disrupting compounds. Studies show decreased male fertility including reduced sperm count and quality, as well as abnormal sperm development.