Exposure to chemicals commonly found in household products, vehicle exhaust, industrial emissions, and other sources may increase blood pressure and risk of hypertension in nonsmoking Americans, a new NIEHS-funded study suggests.

Researchers analyzed data from 4,430 nonsmoking adults participating in the National Health and Nutrition Examination Survey between 2011 and 2018. They found that higher levels of certain volatile organic compounds (VOCs) in urine were linked to increased systolic blood pressure — the pressure in arteries when the heart beats — and a greater likelihood of hypertension. Characterized by persistently high blood pressure, hypertension is a leading cause of heart disease and stroke. The study was published online Nov. 13 in the journal Hypertension.

Filling key knowledge gaps

“Although VOCs are everywhere in our environment, their role in cardiovascular risk among nonsmokers has been underexplored,” said lead author Katlyn McGraw, Ph.D., from Columbia University’s Mailman School of Public Health. “Our study provides much-needed scientific insight, but more research into the effects of these chemicals will be critical moving forward.”

VOCs vaporize easily and are found in indoor and outdoor air, although levels can be up to 10 times higher indoors, noted the authors. Exposure comes from sources like vehicle exhaust, industrial processes, paints, cleaning agents, and tobacco smoke. Also, the body can naturally produce some VOCs through biological processes such as breaking down fats and proteins.

Public health implications

“This is the largest biomonitoring study to explore VOC exposure and its cardiovascular effects in the general nonsmoking U.S. population,” said McGraw. “Our findings suggest that reducing exposure could have significant implications for improving cardiovascular health.”

The study focused on VOCs like acrolein, a byproduct of combustion and industrial activities, and 1,3-butadiene, used in synthetic rubber manufacturing. Participants with the highest levels of these chemicals in their urine had slightly higher systolic blood pressure compared to those with the lowest levels.

Individuals with the highest VOC exposure had a 5-6% greater risk of hypertension than those with the lowest exposure. Across a population as large as the U.S., this could mean thousands of additional cases of hypertension annually.

Need for further study

While the findings are significant, researchers noted some limitations. Single urine samples were used to measure VOC metabolites, which may not reflect long-term exposure. Additionally, some VOCs, such as acrolein and 1,3-butadiene, can be produced naturally in the body, making it challenging to distinguish between external and internal sources of exposure.

“Our findings highlight a link between VOC exposure and hypertension, but they also raise questions needing further investigation,” noted McGraw. For example, the study suggests that older adults and people with pre-existing conditions may be more vulnerable to VOCs.

Looking ahead

Future studies should track individuals over time to better understand how long-term VOC exposure affects cardiovascular health, the researchers noted. The scientists also recommended investigating how combinations of VOCs interact to influence the heart and blood pressure.

“While our research provides important information on VOCs and hypertension in nonsmokers, it’s clear that more work is needed,” McGraw said. “Nevertheless, our study underscores the importance of monitoring environmental exposures as a potential contributor to the burden of hypertension in the U.S.”