A weekly roundup of public health news
Common disinfectant in drinking water linked to kidney disease
A disinfection byproduct found in drinking water supplies is linked to chronic kidney disease, even at lower-than-allowable levels, a new study finds.
The research, published July 2 in JAMA Network Open, found people who had been exposed long-term to higher levels of trihalomethanes in their drinking water had increased risks for chronic kidney disease. Trihalomethanes are chemical compounds that form when chlorine, commonly used for disinfection by most U.S. community water systems, reacts with organic matter.
While the U.S. Environmental Protection Agency sets a maximum contaminant level for trihalomethanes in drinking water supplies, the study found that people exposed to the compounds at even lower that threshold had an increased risk for chronic kidney disease. Previous research has linked trihalomethanes to bladder cancer and adverse pregnancy outcomes such as low birth weights and stillbirths.
The highest risk for chronic kidney disease was found for people exposed to brominated trihalomethanes — forms of the compounds that have been exposed to bromide, a chemical element common in saltwater and coastal regions. Brominated trihalomethanes are not separately regulated in community water, the researchers noted.
Chronic kidney disease, defined by the gradual loss of kidney function, is on the rise, and ranks as one of the top 10 leading causes of U.S. death.
Human reproductive fluids contain microplastics
Microplastics are common in human reproductive fluids, potentially raising concerns for fertility, new findings in Human Reproduction show.
The study, published July 2, examined bodily fluids collected from both women and men, identifying microplastics in 69% of follicular fluid samples and 55% of seminal fluid samples. Follicular fluid is a liquid that surrounds egg cells as they develop inside an ovary, while seminal fluid carries sperm to an egg in the female reproductive tract.
Researchers analyzed microplastics from the fluid samples, finding polytetrafluoroethylene — a non-stick polymer common in cookware, medical devices, textiles and pipe coatings, among other uses — accounted for more than a third of them. Other plastics included polymers found in food packaging, beverage containers, fabrics, furniture and other consumer products.
While the study did not directly assess the impact of the plastics on fertility, researchers said it is possible the pieces could impair egg or sperm quality.
Microplastics, which are particles that are less than 5 millimeters in size, result from the breakdown of plastic products, including those from industrial uses. While their impacts on human health are still emerging, research has linked them to elevated stroke risks from blockages in neck arteries and higher buildup in the brains of people with dementia.
Air pollution contributing to lung cancer in non-smokers
Lung cancer rates are rising in people who have never smoked, and new research says air pollution could be one reason why.
Published July 2 in Nature, the study linked fine-particle air pollution, also known as PM2.5, to rising rates of lung cancer in people who have never used tobacco products. PM2.5 pollution comes from sources such as vehicles, coal-fired power plants and wildfires.
Researchers examined tumors from about 900 people with lung cancer, comparing their genetic mutations to air pollution levels experienced by the patients. They found that never-smokers who lived in heavily polluted areas had more mutations in their tumors. The more pollution a patient was exposed to, the more mutations in their tumors.
Air pollution was also linked to chromosomal damage and accelerated cellular aging, according to the study, which was led by researchers at the University of California-San Diego and the National Cancer Institute. People with high PM2.5 exposure had shortening in their telomeres — sections of DNA found at the end of chromosomes — which interferes with the ability of cells to replicate.
As tobacco use has fallen around the world, lung cancer rates have declined overall. However, lung cancer in people who have never smoked has been on the rise. In the U.S., as many as 40,000 cases of lung cancer each year are diagnosed in people who have never smoked or who have smoked fewer than 100 cigarettes in their lifetime.
Other recent public health news of note includes:
• A new poll from the Civic Health and Institutions Project finds many American disapprove of recent Trump administration’s policies targeting science and medicine. About 48% of respondents in the survey said they were against administration actions such as layoffs at federal health agencies, cuts to research grants and dismantling of the U.S. Agency for International Development. About 21% approved, while the remainder were neutral.
• Black patients who visit hospital emergency departments for opioid overdoses are less likely to receive referrals for outpatient treatment, according to new research in JAMA Network Open. Data on more than 1,600 patients at 10 U.S. hospitals found white overdose patients received referrals 9.6% of the time, compared to a 5.7% rate for Black patients.
• New research in Environmental Science & Technology says targeted land management can reduce wildfire smoke exposure and related deaths. Prescribed burning, a strategy that involves intentionally setting small fires to prevent larger ones, could have could have reduced total smoke exposures by as much as 18% in Northern California in 2020, researchers estimated.
• The U.S. Department of Veterans Affairs should take steps to improve communications on its crisis hotline, the Government Accountability Office says. A new GAO report found some veterans who use the service are redirected to unavailable responders, who are sometimes managing multiple chat at a time. More than 3.8 million interactions were logged from 2021 to 2024 on the crisis line, which is aimed at preventing suicides and other mental health crises among veterans.
The Watch is written by Michele Late, who has more than two decades of experience as a public health journalist.