Peer-reviewed article

Exposure of children to multiple long-term air pollutants (PM_2.5, BC, NO₂) and noise at home and school in accra, Ghana.

Hulme R, Fynn IE, Alli AS, Kyeremateng KA, Lange CL et al. · 1 Sept 2026

Abstract

Sub-Saharan African (SSA) cities have high air and noise pollution levels, yet limited information exists on children's joint exposures at home and school locations - the two most important environments where children spend much of their time. This study characterised schoolchildren's exposure to multiple air pollutants and environmental noise and sound sources within the Accra School Health and Environment Study (ASHES). ASHES involved 1034 children aged 8-12 years from 90 public (73%) and private schools in Accra, Ghana, a major SSA city. Annual mean concentrations of fine particulate matter (PM2.5), nitrogen dioxide (NO2), and black carbon (BC), as well as environmental noise (L day, L night, L den) and sound sources, were derived from land use regression models and linked to geocoded school and home locations for 919 children with valid data. A time-location weighted total exposure estimate was calculated for the air and noise pollution metrics. We also examined children's responses to a noise annoyance survey in relation to their noise exposure levels at home. For air pollutants, median home exposures were 33.8 μg m-3 (PM2.5), 55.5 μg m-3 (NO2), and 5.2 × 10-5m-1 (BC), and corresponding median school exposures were 29.9 μg m-3, 53.5 μg m-3, and 4.9 × 10-5m-1. The time location-weighted total air pollutant exposures for most children surpassed the respective World Health Organization (WHO) guideline. Similarly, median environmental noise levels (in dBA) at home (L den = 66.3 and L night = 54.2) and at school (L day = 62.4) exceeded WHO thresholds for road-traffic noise and Ghana's noise standard for areas with educational facilities, respectively. Pollution levels at home and school were moderately correlated (r [PM2.5] = 0.56; r [NO2] = 0.33; r [L den]= 0.47). On average, children attending public schools or living in lower income areas had higher exposures to both air and noise pollution than their private school (fee-paying) or higher-income counterparts. In contrast, nature-based sounds were more common in higher income areas. Among children exposed to L den noise levels between 65 and 70 dBA, 35% reported being highly annoyed to road traffic noise. Schoolchildren in Accra experience air and noise pollution levels exceeding health-based guidelines and standards. Exposures are unequally distributed, highlighting environmental inequalities with implications for child health, development, and learning.