California Air Resources Board

Principal Investigator/Author: Elizabeth Noth

Contractor: University of California, Berkeley

Sub-contractors: Central California Asthma Collaborative, Little Manila Rising

Contract number: 20RD012

Project Status: Completed June 2026

Relevant CARB programs: Exposure,  Indoor Air

Topic areas: Environmental Justice, Air Pollution Exposure, People at Risk, Health Analysis, Indoor Air Quality & Exposure, Health Effects of Air Pollution, Health & Air Pollution, Community Health, Reducing Disparities, Racial Equity, Health Risk Assessment

Research Summary:

Exposure to particulate and toxic air pollutants such as fine particulate matter (PM2.5), ultrafine particles (UFP), and Volatile Organic Compounds (VOCs) is associated with adverse health effects including asthma, respiratory disease, cardiovascular disease, lung cancer, and poorer neurodevelopmental outcomes in children. CalEnviroScreen, a geographically-based mapping tool that ranks communities by potential exposure, vulnerability, and social economic indicators, shows that many low income and disadvantaged communities (DACs) in California experience higher air pollution and consequent health impacts compared with more affluent neighborhoods. In addition to higher pollutant exposures, DACs are subjected to higher levels of ambient noise, which are also known to negatively affect health. While numerous studies have shown that DACs are subjected to disproportionate exposures to air pollutants and noise, there is less known about the direct impact of different sources, activities, and residential spaces on the total air pollutant and noise exposures for individuals.

The Total Exposures to Air Pollutants and Noise in Disadvantaged Communities project, also known as SPHERE (San Joaquin Valley Pollution and Health Environmental REsearch Study), used indoor and outdoor field studies along with personal monitoring conducted in the Stockton and Fresno areas to assess exposures to pollutants and noise. The communities were selected based on the potential for a wide range of air pollutant sources and different types of residential spaces. The expected results will address knowledge gaps about exposures in DACs by providing information on how personal behaviors and external factors such as building characteristics (housing stock, ventilation and filtration systems, etc), modes of transportation, or participant location contribute to pollutant and noise exposure and indoor air quality (IAQ). The results from this study will be used to assess potential health risks for DAC residents and support the goals of California Assembly Bill 617 (AB 617) by identifying the top localized sources and personal activities that are most responsible for air pollutant and noise exposure in DACs. This study will also provide CARB with data to inform policies for decarbonization.

Keywords: pollutant exposure; indoor air; environmental justice; children’s health; personal exposure; noise exposure; total exposure; San Joaquin Valley; health research

Research Seminar