Jessica A. Broach, Emily W. Harville, Jihoon Jung, David Hsu, Xiuling Zhao, Yoonjung Ahn, Daniel Tong, Siqi Ma, Christopher K. Uejio
The increase in global temperature due to climate change are leading heatwaves to become more frequent and intense and air quality to worsen. Extreme heat and air pollution have been linked to adverse birth outcomes, which could be mitigated by air conditioning (AC). This study examined associations between heat and PM 2.5 with preterm birth (PTB) and low birthweight (LBW) as well as indicators for AC availability. We used Florida birth certificates to conduct a retrospective cohort study of 4,514,067 births (2000 to 2022). Weather data were obtained from the Parameter-elevation Regressions on Independent Sloped Model and exposure based on mother's residential address. Three heatwave definitions were evaluated based on consecutive days with maximum temperature exceeding 90th percentile. PM 2.5 concentrations (µg/m 3) were extracted from the North America Chemical Reanalysis dataset and averaged by trimester. AC exposure was estimated using real estate data. Logistic regression was used to estimate adjusted risk ratios (aRR). We found an increased risk of PTB with increasing heatwave days occurring within a heatwave episode (aRR 1.001, 95% CI 1.001–1.002) during the first trimester and an inverse association in the second (aRR 0.996, 95% CI 0.995–0.997) and third trimesters (aRR 0.921, 95% CI 0.920–0.922). An inverse association with term LBW was observed in the third trimester (aRR 0.981, 95% CI 0.979–0.984). Higher PM 2.5 exposure during the first trimester was associated with increased PTB risk (aRR 1.010, 95% CI 1.008–1.012) and an inverse association with LBW (aRR 0.988, 95% CI 0.984–0.992) with increasing PM 2.5 concentrations in the first trimester. There was no mitigation effect of AC. These results suggest the importance of considering duration and magnitude in defining heat exposure to understand the effects of extreme heat on pregnancy. There is a need for improved comparability of heatwave definitions as climate change continues to accurately assess their public health impacts.
Mia Mathisen Nilsen, Andrea Bellavia, Charlotta Rylander, Dolley Charles, Sandra Huber, Therese Haugdahl Nøst, Tom Wilsgaard, Torkjel M. Sandanger, Tamarra James-Todd, Vivian Berg
Persistent organic pollutants (POPs) occur as correlated mixtures, and serum concentrations may vary over time due to changes in exposure and toxicokinetic processes. We investigated associations between a mixture of POPs measured repeatedly before type 2 diabetes mellitus diagnosis (T2DM). In a longitudinal nested case-control study within the Tromsø Study, serum concentrations of 19 chlorinated POPs were measured at three pre-diagnostic timepoints: T1 (1986/87; 15–21 years before diagnosis, n = 259), T2 (1994/95; 7–13 years before diagnosis, n = 257), and T3 (2001; 0–6 years before diagnosis, n = 260). Lipid-adjusted POP concentrations were analyzed using positive-direction weighted quantile sum (WQS) logistic regression. Single-pollutant analyses were conducted for comparison. The POP mixture was positively associated with subsequent T2DM at T2 [odds ratio (OR) 2.14, 95% confidence interval (CI) 1.34–3.42] and T3 (OR 1.78, 95% CI 1.19–2.66), whereas no association was detected at T1. Cis -heptachlor epoxide and p,p' -DDT received the largest weights at T2. At T3, weights were more distributed, with cis -nonachlor, cis- heptachlor epoxide, β -HCH, PCB-194, and PCB-187 exceeding the equal-weight threshold. Single-pollutant analyses identified similar leading compounds at T2 and T3. POP mixtures measured at T2 and T3 were positively associated with subsequent T2DM. These associations may partly reflect preclinical metabolic changes, altered POPs distribution between adipose tissue and blood, residual confounding, or chance. The findings support the complementary use of mixture and single-pollutant approaches and the value of repeated POP measurements. Larger longitudinal studies are needed to clarify temporality, evaluate potential reverse causation, and formally assess time-varying mixture associations.
Fidel Navarro-García, Aurora Elizabeth Rojas-García, Fernando Bejarano-González, Briscia Socorro Barrón-Vivanco, Cyndia Azucena González-Arias, Miguel Alfonso Ruiz-Arias, Francisco Alberto Verdín-Betancourt, José Francisco Herrera-Moreno, Carlos Alberto Romero-Bañuelos, Néstor Ponce-Ruiz, Yael Yvette Bernal-Hernández, Irma Martha Medina-Díaz
According to the Food and Agriculture Organization of the United Nations (FAO), Mexico uses more than a quarter of Central America's agricultural pesticides. Furthermore, Mexican regulatory agencies still do not recognize the classification of highly hazardous pesticides (HHP) under the Regulations on Registrations, Import and Export Authorizations, and Export Certificates for Pesticides, Plant Nutrients, and Toxic or Hazardous Substances and Materials (PLAFEST) regulation; no explicit national HHP definition exists. The aim of this review was to identify active ingredients (a.i.) historically used in Nayarit that are classified as HHP by internationally accepted classification systems and highlight the differences between them. Seven bibliographic resources, identified through a literature search conducted between October 2024 and July 2025, reported the pesticide sales or use patterns in Nayarit between 1987 and 2021. One hundred and twenty-five different a.i. were observed, of which 44 (35.2%) are HHP according to criteria defined by the FAO and the World Health Organization (WHO). In comparison, 82 (65.6%) are HHP according to the Pesticide Action Network International (PAN). Although most pyrethroids are highly toxic to bees, most of them are not recognized as HHP by FAO/WHO. Organophosphorus and carbamates are the main chemical families of HHP used in Nayarit. Glyphosate, an individual a.i. rather than a chemical family, was also identified as HHP. Dicofol, an organochlorine listed in Annex A of the Stockholm Convention for the global elimination of its use, was reported in retailer sales records. This review demonstrates the differences in the selection of HHP at a state-level assessment revealing that the criteria proposed by PAN allow the inclusion of a greater number of pesticides, in terms of their environmental effects, and a broader understanding of the presence of multiple HHP identified across the available evidence, indicating the potential for mixed pesticide exposure. We consider that a transparent and nationally adopted HHP identification framework is the first step to develop risk prevention strategies and promotion of sustainable alternatives.
Antonio Avila-Uribe, Anomitro Chatterjee, Daire McCoy, Ganga Shreedhar
Air pollution remains a major environmental health challenge, imposing wide-ranging burdens on populations in high- and middle-income countries where it remains a policy-relevant problem. Despite this, existing frameworks for understanding who is most affected, and why, rarely account for the behavioural mechanisms that shape individual vulnerability. This review paper proposes a framework to describe vulnerability to air pollution and situates the role of behaviour in the pathway from pollution to individual outcomes. We consider a broad definition of vulnerability, comprised of three interrelated dimensions: exposure (pollutant concentration encountered by an individual), susceptibility (how much an individual’s well-being is harmed given their exposure), and adaptation (actions taken to reduce exposure or susceptibility). We use this framework to structure a narrative review of multi-disciplinary evidence, touching on a broad set of impacts from physical and mental health to economic outcomes. We show how adaptation behaviour can moderate the relationship between pollution and impacts, while behavioural choices like heating, cooking and ventilation mediate that relationship. Finally, we discuss important overlaps across dimensions of vulnerability, where some components reinforce or attenuate the impacts of others.
