Short-Term Effect of Ambient Air Pollution on Daily Mortality in Three Jordanian Cities: A Time-Series Study

This study involved a multi-city time-series analysis (2015-2019) of daily all-cause (non-accidental) mortality and particulate matter with an aerodynamic diameter less than 10 μm (PM₁₀), nitrogen dioxide (NO₂), and sulfur dioxide (SO₂) in Jordan's three largest cities (Amman, Irbid, Zarqa). City-specific quasi-Poisson models estimated percentage increase of risk per 10-unit increase across single-day lags (0-6 days) and averaged windows as lag (0-1), lag (2-5), and lag (0-5). Multi-pollutant models adjusted the primary pollutant for co-pollutants at lag (0-1). PM₁₀ means were 68.9, 49.0, and 78.7 μg/m³ in Amman, Irbid, and Zarqa, respectively. Amman's average concentration was close to the national annual limit of 70 μg/m³ set by Jordanian air quality standards (JS 1140/2006), while Zarqa's mean level exceeded it. In Amman, PM₁₀ was positively associated with mortality (lag (0-1): 0.59% [0.22-0.96]; lag (0-5): 0.98% [0.40-1.57]); Irbid and Zarqa showed no consistent PM₁₀ associations, and NO₂/SO₂ were generally null across cities. Adjustment for NO₂ and SO₂ did not attenuate Amman's PM₁₀ effect (0.60%-1.19%). Stratified analyses indicated short-lag PM₁₀ and mortality associations were significant among males and older adults in Amman, and cumulative PM₁₀ associations among females in Zarqa. This first national time-series study for Jordan identifies an acute mortality risk from particulate pollution in Amman and suggests inter-city heterogeneity, likely driven by differences in particle composition, sources, exposure, and standards exceedances. These findings support particulate-focused control measures and enhanced risk communication for vulnerable groups.