Emulating Near-Roadway Exposure to Traffic-Related Air Pollution via Real-Time Emissions from a Major Freeway Tunnel System

Incident dementia and long-term exposure to constituents of fine particle air pollution: A national cohort study in the United States

Growing evidence suggests that fine particulate matter (PM_2.5) likely increases the risks of dementia, yet little is known about the relative contributions of different constituents. Here, we conducted a nationwide population-based cohort study (2000 to 2017) by integrating the Medicare Chronic Conditions Warehouse database and two independently sourced datasets of high-resolution PM_2.5 major chemical composition, including black carbon (BC), organic matter (OM), nitrate (NO₃^-), sulfate (SO₄^2-), ammonium (NH₄⁺), and soil dust (DUST). To investigate the impact of long-term exposure to PM_2.5 constituents on incident all-cause dementia and Alzheimer's disease (AD), hazard ratios for dementia and AD were estimated using Cox proportional hazards models, and penalized splines were used to evaluate potential nonlinear concentration-response (C-R) relationships. Results using two exposure datasets consistently indicated higher rates of incident dementia and AD for an increased exposure to PM_2.5 and its major constituents. An interquartile range increase in PM_2.5 mass was associated with a 6 to 7% increase in dementia incidence and a 9% increase in AD incidence. For different PM_2.5 constituents, associations remained significant for BC, OM, SO₄^2-, and NH₄⁺ for both end points (even after adjustments of other constituents), among which BC and SO₄^2- showed the strongest associations. All constituents had largely linear C-R relationships in the low exposure range, but most tailed off at higher exposure concentrations. Our findings suggest that long-term exposure to PM_2.5 is significantly associated with higher rates of incident dementia and AD and that SO₄^2-, BC, and OM related to traffic and fossil fuel combustion might drive the observed associations.

Shared Purpose: Leveraging a Community-Academic Partnership to Increase Local Environmental Health Awareness via Community Science

Environmental factors can lead to disease and health disparities when the places where people live, learn, work, play and pray are burdened by social inequities. Non-formal programs that explicitly connect local environmental exposures and human health could be of great value to communities at greatest risk. The purpose of this work was to co-create relevant and engaging education with youth and community stakeholders of all ages that more explicitly emphasizes the link between the local environment and community members' health through a hands-on community science experience. Our experiences helped strengthen our community-academic partnership and establish a route to create and tailor informal programming to meet local needs and engage people in community science with academic partners. We generated two distinctly different community science neighborhood audit tools designed to differently engage our community partners and inform community participants of their local environments and its role on their health. Through community meetings, we garnered critical insight from our stakeholders. While neither of the tools and accompanying data collected were deemed to be scientifically generalizable, our ongoing and future work has benefited from important lessons learned from their creation and sharing.

Pollutants Concentration during the Construction and Operation Stages of a Long Tunnel: A Case Study of Lowari Tunnel, (Dir–Chitral), Khyber Pakhtunkhwa, Pakistan

Long tunnels with significant overburden, changeable geological conditions, a steep gradient, water infiltration, and heavy traffic flow are susceptible to environmental concerns during both construction and operation. The availability of fresh air and visibility is the most important necessity in excavation for tunnel workers inside the tunnel during the construction phase, as well as those crossing the tunnel during operation. Lowari Tunnel’s tunnel air pollutants were researched. Carbon monoxide (CO), carbon dioxide (CO2), oxygen (O2), hydrogen sulfide (H2S), sulfur dioxide (SO2), nitrogen oxide (NO), ammonia (NH3), nitrogen dioxide (NO2), PM1, PM2.5, PM10, air velocity, dust morphological and particle size distribution analysis are among the parameters under consideration. The findings provide evidence for the development of tunnel air quality.