Lone star ticks, nitrogen dioxide pollution, and a dementia care study highlight this month's research roundup

Researchers at the Yale School of Public Health (YSPH) have uncovered significant racial and economic disparities in the health impacts of long-term exposure to nitrogen dioxide (NO₂)—a common air pollutant produced by vehicles, power plants, and industrial activity.

The national study, published in the Cell Press journal One Earth, is one of the first to jointly assess both exposure and susceptibility differences across U.S. populations, offering critical new insights to guide equitable pollution and health policies.

The Yale team analyzed more than 42 million U.S. death records from 2000 to 2016 and found that racial-ethnic minority populations were both more exposed to NO₂ pollution and more vulnerable to its harmful effects than their non-Hispanic white counterparts. While NO₂ concentrations were generally higher in wealthier counties, racial-ethnic disparities persisted across all income levels.

In low-income counties, non-Hispanic Black populations experienced the highest NO₂-related all-cause mortality burden, with rates more than twice those of non-Hispanic white populations. In high-income counties, the most affected racial-ethnic group varied by location, but non-Hispanic Black communities often faced the greatest health burden. NO₂ exposure was linked to deaths from cardiovascular disease, chronic respiratory conditions, dementias, and other causes.

“Racial-ethnic minorities, particularly those in low-income communities, are facing a double burden of higher exposure and greater health risk,” said senior author Dr. Kai Chen, PhD, associate professor of epidemiology (environmental health sciences) at YSPH and co-faculty director of the Yale Center on Climate Change and Health.

Authors: Lingzhi Chu, Yiqun Ma, Emma Zang, Lei Huang, Kai Chen

Study: Disparities in NO2-related health burden prevalent across race-ethnicity and income groups in the United States

Journal: One Earth

New dementia-friendly community programs in Shanghai, China are having positive impacts on how older adults seek care, according to a published study led by researchers from Fudan University and the Yale School of Public Health (YSPH). The findings support expansion of the novel program model to other areas.

Launched in 2019, the initiative is designed to raise community awareness of cognitive impairment, promote early screening, and provide support for patients and caregivers. Researchers examined health insurance claim data from more than 199,000 Shanghai residents aged 60 and older between 2017 and 2021, comparing communities that implemented the program with those that had not.

The findings show that residents in dementia-friendly communities were 13.7 percent more likely to visit cognitive-related health centers and did so 17.2 percent more often than those in other areas. The effects were most pronounced among people who had never previously sought care for cognitive problems, suggesting the program’s outreach and education efforts are helping individuals recognize symptoms earlier.

The study also found that dementia-friendly communities experienced fewer emergency room visits and had a shift toward using primary care services instead of higher-level hospitals—changes that the researchers said could reduce strain on China’s health system while improving patient outcomes.

“This study shows that even in the short term, community-based initiatives can play a critical role in raising awareness and encouraging earlier diagnosis of cognitive impairment,” said Dr, Xi Chen, PhD, associate professor of public health (health policy) at YSPH and a corresponding author on the study. “Such programs not only benefit individuals and families but also strengthen the health system as a whole.”

Authors: Jingyi Ai, Xi Chen, Jin Feng, Yufei Xie

Study: Early effects of cognitive-impairment friendly community on health care utilization in China: Evidence from administrative data in Shanghai

Journal: Social Science & Medicine

A Connecticut man fell ill after being bitten by a male lone star tick infected with Ehrlichia sp. and Rickettsia amblyommatis, marking a rare, documented case of disease transmission from a male of the species, according to a new report in Clinical Case Reports.

The 52-year-old patient developed flu-like symptoms and swollen lymph nodes after discovering the tick attached to his hip in June 2024. Laboratory testing revealed mild anemia and elevated liver enzymes, though initial screenings for Lyme disease and other common tick-borne infections were negative. His symptoms resolved following a two-week course of doxycycline.

The findings raise concerns as the lone star tick, traditionally found in the southeastern U.S., has been expanding its range into New England.

“This case underscores the need for clinicians in the Northeast to be aware that emerging ticks can harbor multiple pathogens and may present outside the usual diagnostic panels,” said Dr. Goudarz Molaei, senior author of the report and a medical entomologist. “It also challenges the assumption that male ticks pose little or no risk of disease transmission.”