Microplastics linked to heart attacks, strokes
Microscopic bits of plastic can get stuck in human arteries, increasing cardiovascular disease risks, groundbreaking new findings show.
Researchers examined plaque removed from carotid arteries — which carry blood from the heart to the brain — in surgical patients. People who had microplastics in their arterial plaque were almost three times as likely to have a heart attack or stroke or to die within the next three years than patients without them, according to a March 7 study in the New England Journal of Medicine.
In many cases, researchers were able to identify specific chemicals in the tiny, jagged bits of plastic embedded in the arterial plaque. Polyethylene, which is used in drinking bottles and food containers, was detected in the plaque of 58% of patients. Polyvinyl chloride, also known as PVC, which is used in flooring, shower curtains and numerous other household products, was found in 12% of samples. Some of the particles also contained chlorine, the study found.
Microplastics, which are plastic particles smaller than 5 millimeters, commonly enter the human body through eating and drinking, inhalation and skin exposure. Previous research has found microplastics in lung, liver and placenta tissue as well as in blood, urine and breast milk. Babies in particular have been found to have higher levels in their bodies.
The size of microplastics can influence where they accumulate in humans, the new study said. The majority of plastic pieces researchers found in the arterial plaque samples were nanoplastics, which are smaller than 1,000 nanometers and are able to pass through body barriers that larger pieces cannot.
Despite microplastics’ widespread presence, science on their risks in human bodies has been lacking — so much so that the World Health Organization concluded in a 2019 review that there was not enough evidence “to indicate a human health concern.” The new study, which is reportedly the first to directly link microplastics with human disease, may reshape that finding.
The United Nations will meet next month to continue work on a new global pollution treaty aimed at reducing the environmental and human health harms of plastic. Since global plastic production began in the 1950s, output has soared from about 2 million tons a year to about 350 million as of 2017. About 40% of that total is made up of single-use items, which like many plastic products are discarded and degrade but never entirely disappear.
Death rates high for Black infants
New federal data show that Black infants in the U.S. continue to die at higher rates than babies of other races and ethnicities.
For 2019-2021, the overall U.S. infant mortality rate was 5.48 deaths per 1,000 live births. But for Black infants, the rate was almost twice as high, with 10.52 deaths per 1,000 live births, according to a March 4 report from the Centers for Disease Control and Prevention’s National Center for Health Statistics.
Death rates were also high for American Indian and Alaska Native infants, at 7.69 deaths per 1,000 births. The lowest death rates were among Asian infants, at 3.4 per 1,000, followed by white infants, at 4.42, and Hispanic infants, at 4.84.
The report shares data on about 60,300 infant deaths — which numbered 20,800 in 2019, 19,600 in 2020 and 19,900 in 2021. Factors linked to higher risks for infant death include late or nonexistent prenatal care and smoking during pregnancy, the latter of which more than doubled death rates.
Another major risk was pre-pregnancy obesity, rates of which were highest among women who were Black or American Indian and Alaska Native. Pregnant women who were covered by Medicaid were also more likely to experience death of an infant than those with other insurance.
High cholesterol endangers American Indian youth
Many American Indian people — who are at disproportionate risk of death from heart disease — have high cholesterol in their youth, new research shows.
About 55% of American Indian teens ages 15-19 followed as part of a multi-year health project were found to have unhealthy levels of cholesterol. That percentage worsened by age group, with unhealthy cholesterol found in 74% of American Indian young adults ages 20-29 and 78% of those ages 30-39, according to a study in the Journal of the American Heart Association.
Unhealthy cholesterol included high levels of low-density lipoprotein cholesterol, known as LDL, or bad cholesterol; and low levels of high-density lipoprotein cholesterol, known as HDL, or good cholesterol.
High levels of LDL in particular were linked to plaque buildup and cardiovascular incidents such as heart attack and stroke, the researchers found. At the beginning of the study, 40% of participants had high LDL levels while nearly 3% had very high levels.
Almost 20 years later, 9% of people in the study had experienced a stroke, heart attack or heart failure, or had related heart surgery or death. Less than 2% of participants were taking cholesterol-lowering medication at the start of the study and only 8% were taking it five years later, showing a need for interventions.
Previous research has found that American Indian and Alaska Native adults have a higher rate of premature heart attack deaths than people in other racial and ethnic groups. About 21% of American Indian and Alaska Native men under age 55 die from heart attacks, compared to 14% of white, Black and Asian and Pacific Islander men, a study released in November found. Similar rates were also seen for American Indian and Alaska Native women under age 65.
Overall, American Indian and Alaska Native adults in the U.S. tend to have worse health than many other populations groups, with factors such as less access to health care, higher poverty and less education playing a role.
Transportation changes would protect kids from air pollution
Cutting emissions from motor vehicles and supporting climate-friendly transportation options would help millions of U.S. children breathe easier, a new study says.
Policymakers could prevent asthma symptoms from getting worse in more than 56,000 kids, avoid more than 2,500 childhood respiratory infections and save $82 million annually, according to the research, which was published March 12 in Environmental Research Letters.
To get there, leaders in a dozen Northeastern and Mid-Atlantic states would need to work together to limit carbon dioxide emissions from motor vehicles, invest in electric vehicles and boost public transportation, environmental researchers from four major universities found. The changes would lead to declines in air pollution and better protect the health of kids.
The findings were based on an analysis of the Transportation and Climate Initiative, a multi-state “cap and trade” plan that would require fuel suppliers to purchase emission allowances, with proceeds going toward clean transportation programs. Proposed in 2010, the plan eroded in recent years as states faced economic pressures from the COVID-19 pandemic and withdrew from the work.
Despite the initiative’s end, researchers said there is value in exploring the economic and health benefits of addressing climate change through transportation. Other issues lessened by reductions in greenhouse gas emissions from cars include preterm births, childhood bronchitis, emergency department visits and low birth weights, the study said. Children of color, who tend to have higher rates of asthma than white children, would particularly benefit through a reduction in asthma symptoms.
Other recent public health news of interest includes:
• Climate change is increasing demand for water used for crops in California’s San Joaquin Valley, says a new study in PLOS Water.
• Bisphenol A, a chemical coating used in many consumer products, may contribute to obesity in children, a study in mSystems finds.
• Occupational exposure to irritants such as disinfectants and cleaning products are linked to asthma in women, according to new research in Occupational & Environmental Medicine.
• Florida’s Legislature has joined Texas lawmakers in opposing water breaks and other cooling measures that would help protect workers from the harms of high heat.
The Watch is written by Michele Late, who has more than two decades of experience as a public-health journalist.
