Monitoring heatwaves with personal weather stations

A new modeling approach that draws data from personal weather stations can more accurately capture air temperatures across U.S. cities, according to researchers in the Division of Translational Toxicology.

Heatwaves have grown more frequent in recent decades and are expected to intensify in the coming years. This trend is especially concerning in cities due to the urban heat island effect — a phenomenon in which urban areas are several degrees warmer than their surrounding rural areas. Exposure to extreme heat can increase the risk of cardiovascular, respiratory, and kidney diseases. However, most U.S. cities do not monitor weather patterns in enough detail to generate the data scientists need for epidemiological studies.

To address this limitation, the researchers developed a model that estimates hourly air temperatures to which people are exposed with high spatial resolution — meaning it can detect local phenomena such as overheating neighborhoods and the cooling effect of parks. In doing so, they relied on an extensive network of personal weather stations. This approach resulted in accurate coverage of meteorological events such as heatwaves and snowstorms in Philadelphia, New York City, Phoenix, and the Triangle area in North Carolina.

The method also revealed that densely populated neighborhoods are more likely to experience high temperatures and longer, warmer nights. According to the authors, their model could strengthen future epidemiological studies of heat-related health effects. In addition, the approach could improve heatwave alerts that are tailored to specific regions to protect vulnerable populations. (JW) (See related article.)

Citation: Marquès E, Messier KP. 2025. Improved high resolution heat exposure assessment with personal weather stations and spatiotemporal Bayesian models. Geohealth 9(9):e2025GH001451.

Pesticides linked to higher rheumatoid arthritis risk in farm women

Exposure to organochlorine and organophosphate insecticides, and other pesticides, may raise the risk of rheumatoid arthritis (RA) in farm women, according to NIEHS researchers and collaborators. The study is the largest to examine pesticide exposures in relation to RA in this population, and the first to also consider indirect exposures due to applicators’ use.

Growing evidence shows that farming and pesticide use may contribute to RA. However, few studies have examined the effects of specific pesticides on RA risk among women living on farms, where they may be personally or indirectly exposed to pesticides.

To address this gap, the researchers investigated RA incidence among female spouses of licensed private pesticide applicators/farmers in the Agricultural Health Study. They assessed both personal use of 32 specific pesticides by spouses and indirect exposures based on applicators’ use.

They found that personal use of several insecticides – the organochlorine DDT and lindane, the organophosphates coumaphos and malathion, the carbamate called carbofuran, and permethrin – was associated with higher RA risk. Spouses’ RA risk was also associated with personal use of the use of the herbicide metribuzin, and fungicides captan and metalaxyl. Among women who did not personally apply pesticides, RA risk was also greater in those with indirect exposure to the insecticide carbaryl, the herbicide metribuzin and the fungicides maneb/mancozeb.

These findings suggest that both personal and indirect use of certain pesticides may contribute to RA in women. The authors recommend future studies on the role of contemporary insecticides also widely used for residential and public health purposes. (MD)

Citation: Parks CG, Leyzarovich D, Hamra GB, Costenbader KH, Chen D, Hofmann JN, et al. 2025. Associations of specific pesticides and incident rheumatoid arthritis among female spouses in the Agricultural Health Study. Arthritis Rheumatol; doi.org/10.1002/art.43318 [Online 16 July 2025].

How a key protein controls mRNA stability

A protein called tristetraprolin (TTP) promotes the decay of specific mRNAs by interacting with multiple molecular partners, according to NIEHS researchers and their collaborators at the National Cancer Institute.

TTP is an RNA-binding protein that controls the stability of mRNA in cells. Specifically, TTP promotes the decay of a subset of mRNAs that contain particular target motifs. Many of these mRNAs encode cytokines involved in the inflammatory and innate immune responses. Deficiency of TTP in mice leads to a severe systemic inflammatory syndrome with arthritis, osteopenia, and autoimmunity. TTP expression is frequently down-regulated in human cancers, and this is often correlated with poor patient prognosis and tumor progression. However, the precise mechanisms by which TTP controls mRNA stability and influences disease development have remained unclear.

The researchers show that TTP regulates mRNA stability by interacting directly with the CCR4–NOT complex, a large multiprotein complex that degrades mRNA by promoting the stepwise loss of the polyA tail. TTP also promotes mRNA decay by binding to PABPC1, a protein that typically enhances mRNA stability by binding to the polyA tail. The results highlight the ability of TTP to simultaneously interact with different protein molecules to effectively destabilize mRNA, and thus rapidly affect gene expression in response to environmental cues or stress signals.

Future studies will be needed to determine the structural basis of these interactions, and whether altering these interactions could affect the wide range of diseases linked to disrupted mRNA stability. (JW)

Citation: Pekovic F, Lai WS, Corbo J, Hicks SN, Luke K, Blackshear PJ, Valkov E. 2025. Multivalent interactions with CCR4-NOT and PABPC1 determine mRNA repression efficiency by tristetraprolin. Nat Commun 16(1):7528.

A sugar called hyaluronan can help treat viral infections

Treatment with a natural lung-repairing molecule called hyaluronan improves outcomes in mice and humans infected with viruses, according to NIEHS researchers and their collaborators.

Viral lung infections such as influenza and COVID-19 are a major cause of illness and deaths worldwide. Many existing treatments do not prevent adult respiratory distress syndrome (ARDS), a life-threatening condition characterized by severe lung inflammation, tissue damage, and fluid buildup. There is also a critical need for treatments that could be rapidly deployed against a wide range of emerging viral infections.

To address this problem, the researchers examined the potential therapeutic properties of high molecular weight hyaluronan (HMWHA), a sugar found in healthy tissue that reduces inflammation and promotes lung repair. Mice were infected with influenza or SARS-Cov2, which causes COVID-19, and treated with either HMWHA or saline control. HMWHA increased survival rates in mice infected with either virus by reducing inflammation and limiting viral movement through mucus.

In humans, inhaled HMWHA improved outcomes in patients with severe COVID-19, shortening ventilator use and hospital stays among older patients with acute respiratory failure. According to the authors, the study lays the foundation for future clinical trials to evaluate the safety and efficacy of HMWHA as a broad-spectrum antiviral therapy. (JW)

Citation: Stober VP, Trempus CS, Galdi F, Martin NP, Gladwell W, Cronce M, Cox JS, Keasling JD, Budzik J, Chen SH, Sakamachi Y, Li JL, McGee CA, Zaccaro DJ, Der JS, Tucker CJ, Scappini E, Campos Gomez J, Rowe SM, Cowman MK, Barkauskas CM, Lee PJ, Markovetz MR, Button B, Hill DB, Erxleben DA, Hall AR, Liu J, Xu Y, Pedone C, Antonelli-Incalzi R, Matalon S, Savani RC, Garantziotis S. 2025. Hyaluronan ameliorates viral pneumonia in mice and humans by inhibiting E2F1 transcription factor. Am J Respir Cell Mol Biol; doi: 10.1165/rcmb.2025-0173OC [Online 28 Jul 2025]

Simplifying single-cell datasets

A powerful computational tool called GIBOOST enhances the visualization and interpretability of single-cell datasets to provide critical biological insights, according to NIEHS researchers and their collaborators.

High-dimensional, single-cell data consists of complex measurements of many features from individual cells, such as gene expression, protein levels, and signaling activity. These datasets are important for characterizing the molecular mechanisms underlying various diseases. However, these datasets are often challenging to visualize and interpret, limiting insights into disease progression or drug responses.

To address this challenge, the researchers developed a computational framework called GIBOOST, which is driven by artificial intelligence (AI). GIBOOST offers a holistic view of the data by combining the strengths of existing tools while minimizing their limitations. The tool reduces the complexity of the data while preserving essential features, enabling effective visualization and interpretation.

The researchers showed that GIBOOST provides superior visualization of cell-cell communication and cellular transitions during processes such as sperm cell production and placenta development compared with standard methods. This approach could enable researchers to obtain a more comprehensive understanding of complicated, dynamic biological processes across different tissues and disease states. Ultimately, this information could support the development of effective treatments and the promotion of optimal health. (JW)

Citation: Atitey K, Li J, Papas B, Egbon OA, Li JL, Kana M, Aimola I, Anchang B. 2025. Boosting data interpretation with GIBOOST to enhance visualization of complex high-dimensional data. Brief Bioinform 26(4):bbaf415.

Chemical health hazards following train derailment identified

A new literature review by NIEHS researchers and their collaborators highlights the potential health consequences of chemical releases following disasters such as train derailments.

In 2023, a Norfolk Southern Railway train derailed in East Palestine, Ohio, exposing nearby residents to toxic chemicals released into the air, water, and soil. To prevent an explosion, emergency responders conducted a vent and burn of five rail cars containing a carcinogenic gas called vinyl chloride.

To better understand the disaster’s potential health hazards, the researchers conducted a literature review of studies on 22 chemicals that may have been released after the derailment. Their analysis revealed that eight of these chemicals can irritate the skin, eyes, or respiratory tract, findings consistent with symptoms reported by community members and first responders.

The team also found that five of the chemicals are known to cause cancer, two may damage the immune or nervous system, and one could harm reproductive organs or fetal development. In addition, the researchers identified knowledge gaps that should be addressed in future studies. According to the authors, these insights could inform communication and health-monitoring strategies related to toxic chemical releases during derailments and other disasters. To learn more about this study, please see NIEHS Phased Scoping Review of the East Palestine, Ohio Train Derailment. (JW)

Citation: Lunn RM, Clemons M, Blain R, Mahabir S, Mehta SS, Rooney AA, Singh A, Smith-Roe S, Taylor KW, Tracy W, Zarco M, Fenton SE. 2025. Identifying the known and unknown health hazard information for chemical disasters: a phased scoping review of the East Palestine, Ohio train derailment. J Expo Sci Environ Epidemiol 35(6):888-906.

Improving immunotherapies for allergic asthma

A new study has revealed a specific type of lung immune cell that reduces allergic reactions to inhaled allergens, according to NIEHS researchers and their collaborators.

Allergic asthma is a common disease triggered by immune reactions to allergens such as pollen, dust mites, and animal dander. Symptoms can include coughing, wheezing, shortness of breath, and chest tightness. Currently, there remains an urgent need for immunotherapies that work quickly and improve patient adherence.

Toward this goal, the researchers investigated lung conventional dendritic cells (cDCs), which help promote tolerance to allergens. The results revealed that type 2 cDCs (cDC2s) express high levels of a protein called CD301b. These cells strongly activated T-regulatory (Treg) cells, which are known to suppress allergic responses. When transferred to mice, these cDC2s induced immunological tolerance to inhaled allergens.

The findings shed light on how cDCs and Treg cells develop and function in the lung, broadening the understanding of the cellular and molecular basis of asthma. According to the authors, future studies focusing on the newly characterized cDC2s may pave the way for improved strategies to prevent or treat allergic asthma. (JW)

Citation: Wilkinson CL, Nakano K, Grimm SA, Whitehead GS, Arao Y, Blackshear PJ, Karmaus PW, Fessler MB, Cook DN, Nakano H. 2025. GM-CSF-dependent CD301b+ mouse lung dendritic cells confer tolerance to inhaled allergens. Nat Commun 16(1):8547.

Hair straightener/relaxer use may be linked to pancreatic cancer, thyroid cancer

Women who use hair straighteners may face a higher risk of developing various types of cancer, according to a new study by NIEHS researchers and their collaborators.

Hair products such as straighteners and chemical relaxers are widely used, despite previous findings linking them to increased risks of reproductive cancers (breast, ovarian, and uterine). Whether these products are associated with other types of cancer has been less clear. To help address this knowledge gap, the researchers analyzed data from 46, 287 women aged 35-74 years, tracking cancer diagnoses over an average follow up period of 13 years.

The results showed that use of hair straighteners and chemical relaxers at the time of enrollment was linked to higher rates of thyroid cancer, non-Hodgkin lymphoma, and pancreatic cancer. The study participants were 84% non-Hispanic White women; thus, the authors emphasized the need for future research in more racially and ethnically diverse populations — particularly with more representation of Black and Hispanic women, who tend to use these products more frequently.

According to the authors, the findings broaden the understanding of potential health risks associated with chemical hair products. More research is needed to identify which ingredients contribute to cancer development and to clarify the biological mechanisms that may be involved in this process. (JW)

Citation: Bailey JT, Chang CJ, Gaston SA, Jackson CL, Sandler DP, O'Brien KM, White AJ. 2025. Use of hair straighteners and chemical relaxers and incidence of non-reproductive cancers. J Natl Cancer Inst djaf280.

Airborne phthalates linked with high blood pressure

Exposure to phthalates emitted from industrial sources may increase the risk of high blood pressure, according to an NIEHS researcher and collaborator.

Phthalates are widely used chemicals found in personal care products, pharmaceuticals, and medical devices. As endocrine-disrupting chemicals (EDCs) that can be released into the air, they interfere with hormones and have been linked to a range of health problems. Although other EDCs have been associated with adverse cardiovascular outcomes, the potential relationship between phthalate exposure and high blood pressure, or hypertension, remains unclear.

To investigate this question, the researchers analyzed interview responses and blood pressure measurements from 47,465 women participating in the Sister Study. They estimated exposure to phthalates based on a national air toxin database linked to participants’ home addresses. The results showed that higher levels of airborne phthalates were associated with an increased risk of hypertension, especially among women who were not non-Hispanic White.

Given the widespread presence of phthalates and the growing prevalence of hypertension, the findings have important public health implications. The authors noted that air quality regulations and environmental policies may be needed to reduce phthalate emissions. They also highlighted the importance of future studies to clarify how these chemicals may alter biological pathways that lead to hypertension or related health conditions. (JW)

Citation: Xu J, Sandler DP. 2025. Airborne phthalate exposures and hypertension in the Sister Study. J Hazard Mater 496:139311.

How air pollution affects breast cancer in the U.S.

A large analysis, U.S.-based study led by NIEHS researchers and their collaborators shows that several air pollutants are linked to a higher risk of breast cancer.

Breast cancer incidence has steadily increased in the U.S. in recent decades. Previous research suggests that exposure to environmental chemicals and pollutants may contribute to this trend. For example, air pollution contains molecules that can act as carcinogens and can disrupt hormones, potentially contributing to the development of breast cancer. Yet limited evidence exists on how these associations may vary by breast tumor subtype or geographically, due to differing sources of pollutants.

The researchers analyzed data from five large U.S. cohorts, including more than 28,000 women diagnosed with breast cancer. The results revealed a positive association between residential exposure to nitrogen dioxide and breast cancer risk, consistent with previous studies. In addition, outdoor levels of fine particulate matter were associated with a higher breast cancer risk among participants living in the Midwest. Exposure to both fine particulate matter and ozone were associated with a higher risk of hormone receptor-negative tumors, which tend to grow more aggressively and respond to fewer treatment options.

According to the authors, air pollution may contribute to a larger number of breast cancer cases than previously recognized, given widespread environmental exposures and high rates of the disease. (JW)

Citation: White AJ, Hart JE, Quraishi SM, Bookwalter DB, Sweeney MR, Spalt EW, Hendryx MS, Irvin VL, Lane DS, Shadyab AH, Sealy-Jefferson S, Neuhouser ML, Whitsel EA, Kaufman JD, Laden F, Sandler DP. 2025. Air pollutants and breast cancer risk: a parallel analysis of five large US prospective cohorts. Am J Public Health 115(12):2030-43.