Human health risk of particle exposure in outdoor environments in southwestern Pennsylvania

Spatial distribution and health risk implications of elemental hazard quotients in selected Nigerian cities

The disease burden associated with air pollution is now comparable to that of other major global health threats, including poor nutrition and tobacco use. This study employed the gravitational settling method to collect airborne particles in selected Nigerian cities. The cities include; Benin, Kano, Abuja, Lagos, Enugu, and Calabar. Airborne particles were allowed to settle naturally into containers fitted with funnels and placed outdoors at various sub-locations within each State. Sampling was conducted over a nine-month period from January to September 2023. The collected sediments were analyzed spectroscopically using a UV Visible (UV-VIS) Spectrophotometer CE 1101 to determine concentrations of cadmium (Cd), nickel (Ni), lead (Pb), and manganese (Mn). Results revealed that hazard quotient (HQ) values for all analyzed metals exceeded the recommended safe limit of 1 across all locations. In Benin City, nickel and lead recorded HQ values of 5.5 and 4.0, respectively. Enugu showed particularly elevated levels, with manganese (Mn) at HQ 16 and lead (Pb) at HQ 5, attributed to industrialization and vehicular activities. In Kano, HQ values for lead (Pb) and nickel (Ni) were 8.0 and 4.9, respectively. Abuja recorded HQ values of 6.0 for lead (Pb) and 4.9 for nickel (Ni), likely linked to recycling and agricultural activities. Lagos and Calabar also exhibited elevated HQ values, particularly for lead and nickel. Elevated exposure to these toxic elements can pose potential health risks, including neurological, respiratory, and allergic effects, to exposed populations.

Disparities in fine particulate matter (PM2.5) monitoring capacity in eastern Canada

Standards for air pollution are becoming more stringent. Canada will update the annual average fine particulate matter (PM2.5) standard to 8 µg m−3 in 2030, which questions the adequacy of existing PM2.5 monitoring capacity for evaluating potential exceedances and exposure risk at community level. Although PM2.5 monitoring has expanded beyond regulatory monitors to include low-cost sensors, concerns remain regarding inequalities in its effective coverage and thus data representativeness for exposure estimations. Understanding the connections between PM2.5 monitor density, surface exposure, and neighbourhood socio-economic deprivation and health vulnerability is important for addressing compounded inequities. In this study, we applied locally adaptive kernel density estimation to calculate total PM2.5 monitor density from 2020 to 2024 in Ontario, Quebec, and Atlantic Canada. Local bandwidths were defined for each monitored location by considering the surrounding variability of surface PM2.5 concentrations and its sensitivity to distinguish exceedances. Suburban communities of Montreal, Toronto, near-border regions of Windsor and Niagara, southeast Kitchener, and remote communities in northwest Ontario had observed multiple disparities, with more pronounced socio-economic marginalization, higher surface exposure, but inadequate monitoring. Based on mixed-effects logistic regression, residential instability and situationally vulnerable populations had 25% and 54% higher odds of being deprived in PM2.5 monitoring capacity, respectively, after controlling for surface PM2.5 and emission facility density. Assessments of random-effects also suggested the importance of locally adapted strategies to account for provincial and inter-municipality variations in monitoring disparities among socio-economically marginalized groups and populations with physical or psychological disabilities. Overall, our findings inform vulnerable communities in need of monitoring expansion for precise air quality control and health risk assessments in light of the new standard.

Urban environment, health, and equity

Background: Urban residents are exposed to multiple environmental stressors, but robust evidence on inequities in environmental exposure and associated health and well-being outcomes remains limited. Aim: To assess inequities in residential exposure to air pollution (PM2.5, PM10, and NO2), traffic noise (road, railway, and aircraft) and greenness (NDVI within 300 m), and to characterize associations with self-reported symptoms and annoyances. Methods: The study population comprised 46,282 adults (18–84 years) residing in Stockholm County, Sweden, who responded to the Swedish National Environmental Health Survey 2023. Residential exposure (dichotomized) was based on geocoded address coordinates and stratified by socioeconomic status (SES) and building type. Logistic regression estimated adjusted odds ratios (OR) with 95% confidence intervals (95% CI) and tested effect modification via interaction terms. Results: Apartment residents were more often exposed to air pollution and noise and had less surrounding greenness than house residents. SES-stratified analyses revealed exposure-specific patterns, but no consistent overall trends. Air pollution exposure was associated with perceived poor outdoor air quality (NO2: OR = 3.22; 95% CI = 2.75–3.79), traffic noise with, for example, high noise annoyance (road traffic: OR = 4.59; 95% CI = 4.02–5.26), and greenness, for example, with lower perceived indoor heat stress during summer (OR = 0.83; 95% CI = 0.79–0.88). Self-reported health and well-being varied by SES and building type. Conclusions: Our study reveals concentrated environmental stressors in dense residential areas and highlights multidimensional environmental inequities. Environmental exposure was associated with self-perceived health and well-being, underscoring the need for integrated, system-based policies, such as One Health, to promote sustainable urban well-being.

Age-dependent health risk assessment and excess lifetime cancer risk from radon in groundwater of northeastern Iraq

Abstract Naturally occurring radon in groundwater represents a significant public health concern due to exposure through both ingestion and inhalation. This study investigated radon concentrations across 30 groundwater samples collected from northeastern Iraq, together with associated physicochemical parameters and radiological risk assessments. Measured radon concentrations spanned from 2.9 to 29.7 Bq L−1, with a mean of 12.5 Bq L−1. Approximately 43.3 % of the sampled sites exceeded the USEPA guideline, whereas all concentrations remained below the WHO and UNSCEAR limits. Radiological health risk indicators, including annual effective dose via ingestion and inhalation pathways and excess lifetime cancer risk, were evaluated across three different age groups. Although the overall total annual effective dose remained beneath the WHO recommended limit of 0.1 mSv y−1, infants recorded higher dose values than both children and adults, with five sampling locations surpassing this threshold specifically for the infant group. Excess lifetime cancer risk estimates across all age categories fell within USEPA acceptable boundaries. Pearson correlation, skewness, kurtosis, and Shapiro-Wilk statistical tests were applied to examine relationships between radon levels and water quality indicators. Findings highlight the need for targeted mitigation interventions, continuous environmental monitoring, and community awareness initiatives to reduce long-term waterborne radon health risks.

Health risk assessment and oxidative potential prediction based on atmospheric PM2.5 and associated metals in metro stations.

Research on indoor air quality in metro stations has primarily focused on monitoring air pollutants and source apportionment, while potential health effects have received less attention. To address this gap, we collected PM2.5 samples from platforms and concourses in five metro stations in Shanghai to assess health risks and develop a predictive model for atmospheric oxidative potential (OP). The study showed that the concentrations of PM2.5 and metal compositions were higher on the platforms than in the concourses, but there was no significant difference between urban and suburban stations. Fe, Co, Cr, and Mn were substantially enriched in the metro environment, as indicated by concentration ratios among sampling sites. Further health risk assessment of these enriched elements revealed that the hazard quotient (HQ) for Mn and the excess lifetime cancer risks (ELCRs) for Co and Cr were elevated, suggesting that these three elements should be prioritized in indoor air quality management. The atmospheric OP on the platforms was higher than that in the concourses, consistent with the distribution of PM2.5 concentrations. Spearman correlation analysis demonstrated that Mn, Fe, and Co were strongly positively correlated with OP. A multiple linear regression model developed to predict atmospheric OP revealed that Mn concentration was an effective predictor of atmospheric OP in metro stations (adj. R2 = 0.795). Our results provided essential references for controlling and predicting air pollutants in metro stations.

Human health risk assessment of heavy metal pollution in airborne dust from Zakho City, Iraq