05
Oct
Exposure to Widely Used Bug Sprays Linked to Rheumatoid Arthritis
(Beyond Pesticides, October 5, 2022) Exposure to widely used synthetic pyrethroids, present in many mosquito adulticides and household insecticides like RAID, is associated with a diagnosis of rheumatoid arthritis, according to research published in Environmental Science and Pollution Research. This is the latest pesticide-induced disease associated with this dangerous class of chemicals – a harm to individual Americans that the U.S. Environmental Protection Agency (EPA) is not considering when it registers pesticides. To remedy the major deficiencies in EPA’s reviews, and protect residents from chronic disease, more and more communities are transitioning to safer, organic pest management practices that do not require pyrethroids and other toxic synthetic pesticides.
Rheumatoid arthritis (RA) is an autoimmune disease that causes systemic inflammation throughout the body, resulting in progressive damage to an individual’s joints. In the United States, roughly 1.3 million adults suffer from RA, accounting for nearly 1% of the adult population. Health care costs associated with the disease reach nearly $20 billion annually.
To better understand the etiology behind the disease, an international team of researchers from China, Illinois, and Missouri analyzed data from the 2007-2014 National Health and Nutrition Examination Survey (NHANES), a long-running program that began in the early 1960s and has since become a continuous program focused on American health and nutrition measurements.
Exposure to synthetic pyrethroids was captured by analyzing levels of a metabolite called 3-phenoxybenzoic acid (3-PBA), a breakdown chemical that most synthetic pyrethroids form as they degrade. In their analysis, researchers include 4,384 individuals, including 278 RA patients that have been diagnosed with the disease.
Results generally find that higher levels of 3-PBA are associated with RA. A crude model that does not account for many confounders finds that when compared to individuals in the lowest quartile of pyrethroid exposure, those with high 3-PBA levels are associated with a 50% increased chance of having RA. However, after controlling for sex, race/ethnicity, education, body mass index, family poverty income, level of education, marital status, smoking status, alcohol usage, physical activity, hypertension, and urinary creatinine, this association lowers to a still concerning 23%. One of the most significant associations between urinary metabolites and RA is for individuals aged 40 to 59, who have an 82% increased risk of developing the disease.
“Taken together, our study suggested that pyrethroid pesticide exposure was positively associated with RA,” the study reads. “In addition, higher levels of pyrethroid exposure were linearly associated with increased prevalence of RA in adults.”
Synthetic pyrethroids are one of the most frequently detected chemicals in Americans’ bodies. Prior NHANES data shows that 78% of adults and 79% of children have some level of 3-PBA in their urine. These chemicals have increasingly come to replace organophosphate insecticides in homes, for mosquito management, in food production, and in local parks and playing fields. Often billed as “safe as chrysanthemum flowers,” they are less acutely toxic than organophosphates, but it is increasingly evident that they pose insidious chronic risks to health that are no less concerning than the hazardous pesticides that came before them.
In addition to the association with RA, research published in 2020 finds that synthetic pyrethroid exposure is associated with higher risks of death from all causes, and particularly cardiovascular disease. Yet, perhaps most concerning are impacts to children’s health. Multiple studies have been published linking synthetic pyrethroids to developmental problems in children. Most recently, a study published in Neurotoxicology finds that even infants with low levels of synthetic pyrethroid exposure at 6-8 months of age experience an association with increased risk of language development delays at age two. Additionally, a 2019 Danish study found that higher concentrations of pyrethroid insecticides correspond to higher rates of ADHD in children. In addition to motor skills and learning development, young boys exposed to synthetic pyrethroids are more likely to experience early onset of puberty.
Much of this exposure can occur from eating a diet laden with these toxic pesticides. However, those that switch from a conventional to organic diet can significantly reduce the amount of pesticide in their body, as evidenced by drastic drops in urinary 3-PBA after going organic. In fact, children that eat organic are more likely to score higher on cognitive tests than those that consistently eat conventional, pesticide-contaminated food.
Yet for many low-income and Black, Indigenous, People of Color (BIPOC) communities around the country, eating organic is not likely to limit all exposures. In public housing, synthetic pyrethroids are often used as bug sprays for common household pests that would not have been a problem if proper maintenance was kept up. Research finds that, after sprayed, synthetic pyrethroids can remain on surfaces for up to a year, representing a continuous source of re-exposure.
Synthetic pyrethroids are increasingly the first choice for mosquito management in many communities around the country. Just last week, New York City doused a number of neighborhoods throughout the city with the product Anvil 10+10, containing the synthetic pyrethroid sumithrin. Beyond Pesticides urged the NYC Department of Health to avoid the use of these adulticides. One reason noted in the letter is the risk to young children, pregnant mothers, and communities of color already exposed to disproportionate pesticide use. While a 2021 study found that disease carrying mosquitoes are found at higher rates in lower socioeconomic areas, a study published earlier this year found that children’s exposure to mosquito control operations was associated with significant increases in the risk of allergies and respiratory diseases. Put together, these data tell a story of low-income communities, and the children living there, being sprayed more often and placed at greater risk as a result of a lack of investment in maintenance and infrastructure that would prevent pest problems before they start.
While these risks are well-documented by independent scientific studies, a 2019 review of the available literature by EPA dismisses these concerns at the behest of an industry group dubbed the Pyrethroid Working Group. Rather than increased protections from synthetic pyrethroids, EPA in recent years has expanded their allowed uses, and the amounts applicators are allowed to apply, increasing exposure levels for everyday American and their children.
Communities aiming to address these environmental injustices are urged to consider a more holistic pest management approach – help residents find affordable organic food or grow their own, employ safer mosquito management, and take an organic pest management approach. For municipalities, schools, and homes, right now is the season to transition lawns and landscapes to organic. Take action today to urge your local leaders to bring these practices to your hometown.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
With weak pesticide regulations in many developing countries including no laws and regulations for different home bug sprays easily avalable in all stores, the problem is much wider and bigger.
October 8th, 2022 at 3:08 am