Microplastics have become a more significant issue as concern has grown around plastic pollution and its environmental effects. Ongoing research has looked into biodegradability and ways to increase this. However, more recent research has focused on how plastic pollutants can damage biological organisms.
Category: Ecotoxicology
What ‘Chornobyl dogs’ can tell us about survival in contaminated environments
Read the full story from Columbia University.
In the first step toward understanding how dogs — and perhaps humans — might adapt to intense environmental pressures such as exposure to radiation, heavy metals, or toxic chemicals, researchers found that two groups of dogs living within the Chernobyl Exclusion Zone showed significant genetic differences between them. The results indicate that these are two distinct populations that rarely interbreed. While earlier studies focused on the effects of the Chernobyl Nuclear Power Plant disaster on various species of wildlife, this is the first investigation into the genetic structure of stray dogs living near the Chernobyl nuclear power plant.
Regulating ‘forever chemicals’: 3 essential reads on PFAS
by Jennifer Weeks, The Conversation
The U.S. Environmental Protection Agency is preparing to release a draft regulation limiting two fluorinated chemicals, known by the abbreviations PFOA and PFOS, in drinking water. These chemicals are two types of PFAS, a broad class of substances often referred to as “forever chemicals” because they are very persistent in the environment.
PFAS are widely used in hundreds of products, from nonstick cookware coatings to food packaging, stain- and water-resistant clothing and firefighting foams. Studies show that high levels of PFAS exposure may lead to health effects that include reduced immune system function, increased cholesterol levels and elevated risk of kidney or testicular cancer.
Population-based screenings over the past 20 years show that most Americans have been exposed to PFAS and have detectable levels in their blood. The new regulation is designed to protect public health by setting an enforceable maximum standard limiting how much of the two target chemicals can be present in drinking water – one of the main human exposure pathways.
These three articles from The Conversation’s archives explain growing concerns about the health effects of exposure to PFAS and why many experts support national regulation of these chemicals.
1. Ubiquitous and persistent
PFAS are useful in many types of products because they provide resistance to water, grease and stains, and protect against fire. Studies have found that most products labeled stain- or water-resistant contained PFAS – even if those products are labeled as “nontoxic” or “green.”
“Once people are exposed to PFAS, the chemicals remain in their bodies for a long time – months to years, depending on the specific compound – and they can accumulate over time,” wrote Middlebury College environmental health scholar Kathryn Crawford. A 2021 review of PFAS toxicity studies in humans “concluded with a high degree of certainty that PFAS contribute to thyroid disease, elevated cholesterol, liver damage and kidney and testicular cancer.”
The review also found strong evidence that in utero PFAS exposure increases the chances that babies will be born at low birth weights and have reduced immune responses to vaccines. Other possible effects yet to be confirmed include “inflammatory bowel disease, reduced fertility, breast cancer and an increased likelihood of miscarriage and developing high blood pressure and preeclampsia during pregnancy.”
“Collectively, this is a formidable list of diseases and disorders,” Crawford observed.
2. Why national regulations are needed
Under the Safe Drinking Water Act, the Environmental Protection Agency has the authority to set enforceable national regulations for drinking water contaminants. It also can require state, local and tribal governments, which manage drinking water supplies, to monitor public water systems for the presence of contaminants.
Until now, however, the agency has not set binding standards limiting PFAS exposure, although it has issued nonbinding advisory guidelines. In 2009 the agency established a health advisory level for PFOA in drinking water of 400 parts per trillion. In 2016, it lowered this recommendation to 70 parts per trillion, and in 2022 it reduced this threshold to near-zero.
But many scientists have found fault with this approach. EPA’s one-at-a-time approach to assessing potentially harmful chemicals “isn’t working for PFAS, given the sheer number of them and the fact that manufacturers commonly replace toxic substances with ‘regrettable substitutes – similar, lesser-known chemicals that also threaten human health and the environment,” wrote North Carolina State University biologist Carol Kwiatkowski.
In 2020 Kwiatkowski and other scientists urged the EPA to manage the entire class of PFAS chemicals as a group, instead of one by one. “We also support an ‘essential uses’ approach that would restrict their production and use only to products that are critical for health and proper functioning of society, such as medical devices and safety equipment. And we have recommended developing safer non-PFAS alternatives,” she wrote.
3. Breaking down PFAS
PFAS chemicals are widely present in water, air, soil and fish around the world. Unlike with some other types of pollutants, there is no natural process that breaks down PFAS once they get into water or soil. Many scientists are working to develop ways of capturing these chemicals from the environment and breaking them down into harmless components.
There are ways to filter PFAS out of water, but that’s just the start. “Once PFAS is captured, then you have to dispose of PFAS-loaded activated carbons, and PFAS still moves around. If you bury contaminated materials in a landfill or elsewhere, PFAS will eventually leach out. That’s why finding ways to destroy it are essential,” wrote Michigan State University chemists A. Daniel Jones and Hui Li.
Incineration is the most common technique, they explained, but that typically requires heating the materials to around 1,500 degrees Celsius (2,730 degrees Fahrenheit), which is expensive and requires special incinerators. Various chemical processes offer alternatives, but the approaches that have been developed so far are hard to scale up. And converting PFAS into toxic byproducts is a significant concern.
“If there’s a lesson to be learned, it’s that we need to think through the full life cycle of products. How long do we really need chemicals to last?” Jones and Li wrote.
Editor’s note: This story is a roundup of articles from The Conversation’s archives.
Jennifer Weeks, Senior Environment + Energy Editor, The Conversation
This article is republished from The Conversation under a Creative Commons license. Read the original article.
“Plasticosis:” New disease in birds highlights dangers of microplastics
Read the full story in New Atlas.
Scientists have described a new disease called plasticosis, which is directly caused by – you guessed it – plastic waste in the environment. While the disease has so far only been identified in the digestive tracts of seabirds, the scale of the problem suggests it could be widespread in other species and different parts of the body.
How widespread are these toxic chemicals? They’re everywhere.
Read the full story in the New York Times.
Polar bears in the Arctic and plankton in the Pacific. Cardinals in Atlanta and crocodiles in South Africa.
While concern about PFAS compounds, also known as “forever chemicals” because they break down very slowly, has largely focused on people, the pollutants have also been detected in wildlife. Now, a review of research made public on Wednesday by the Environmental Working Group, a nonprofit advocacy organization that focuses on environmental safety, shows PFAS turning up in hundreds of wild animal species around the world.
In people, some of these chemicals are linked to cancers, developmental issues, reduced immune function, hormonal interference and heightened cholesterol. Last year, the Environmental Protection Agency found there was virtually no safe level in humans for two of the most widely used PFAS chemicals and proposed designating them as hazardous.
To get a sense of contamination in wildlife, researchers at the Environmental Working Group reviewed more than a hundred studies and created a map from their survey.
Tracing the flow of forever chemicals into waterways and wildlife
Read the full story at Undark.
In Maine, PFAS compounds in surface water and groundwater have reached the sea, where they’re turning up in marine life.
Virus plus microplastics equal double whammy for fish health
Read the full story from the Virginia Institute of Marine Science.
Microplastics — tiny particles generated as plastics weather and fragment — pose a growing threat to ecosystem and human health. A new laboratory study shows these threats extend beyond direct physical or chemical impacts, revealing that the presence of microplastics increases the severity of an important viral fish disease.
Bees exposed to common weedkiller via wildflower nectar
Read the full story from Trinity College Dublin.
Bees may be at risk from exposure to glyphosate — an active ingredient in some of the EU’s most commonly used weedkillers — via contaminated wildflower nectar, according to new research. Residues of glyphosate have previously been found in nectar and pollen collected by bees foraging on plants that have been selectively targeted with weedkiller, but this time it has been reported in unsprayed wildflowers growing near sprayed fields.
Microfibers in the Mediterranean Sea are floating homes for bacteria
Read the full story from PLOS.
Almost 200 species of bacteria colonize microfibers in the Mediterranean Sea, including one that causes food poisoning in humans, according to a new study led by Maria Luiza Pedrotti of Sorbonne Université, published November 30 in the open-access journal PLOS ONE.
Alligators exposed to ‘forever chemicals’ show autoimmune impacts: study
Read the full story in The Hill.
Alligators exposed to “forever chemicals” in North Carolina’s Cape Fear River may be experiencing adverse clinical and autoimmune effects, a new study has found.
In addition to showing genetic indicators for immune system impacts, the animals had many unhealed or infected lesions, according to the study, published on Thursday in Frontiers in Toxicology.
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