Source sector and fuel contributions to ambient PM2.5 and attributable mortality across multiple spatial scales.

Ambient fine particulate matter (PM2.5) is the world's leading environmental health risk factor. Reducing the PM2.5 disease burden requires specific strategies that target dominant sources across multiple spatial scales. We provide a contemporary and comprehensive evaluation of sector- and fuel-specific contributions to this disease burden across 21 regions, 204 countries, and 200 sub-national areas by integrating 24 global atmospheric chemistry-transport model sensitivity simulations, high-resolution satellite-derived PM2.5 exposure estimates, and disease-specific concentration response relationships. Globally, 1.05 (95% Confidence Interval: 0.74-1.36) million deaths were avoidable in 2017 by eliminating fossil-fuel combustion (27.3% of the total PM2.5 burden), with coal contributing to over half. Other dominant global sources included residential (0.74 [0.52-0.95] million deaths; 19.2%), industrial (0.45 [0.32-0.58] million deaths; 11.7%), and energy (0.39 [0.28-0.51] million deaths; 10.2%) sectors. Our results show that regions with large anthropogenic contributions generally had the highest attributable deaths, suggesting substantial health benefits from replacing traditional energy sources.

Lung function abnormalities among garri processing workers in Ogbomoso, Nigeria.

BACKGROUND: Local production of garri (cassava crisps) is associated with air pollution and consequently lung function abnormalities among garri processing workers. This study was aimed at describing lung function abnormalities among Nigerians engaged in cassava crisps (garri) processing. METHODS: A total of 351 workers and 351 controls were recruited at garri factories in Ogbomoso, Nigeria by multistage random sampling technique. Lung functional abnormalities were defined according to standardised European Respiratory Society/American Thoracic Society guidelines. Data analysis was performed using the IBM SPSS statistics version 22.0. RESULTS: The mean age of patients was similar to that of controls (41.7 ± 14.9 vs. 41.6 ± 14.7 yearsP = 0.960). Larger proportion (46.2%) of cassava crisps factory workers had abnormal ventilatory function parameters compared to 6.8% in controls (P < 0.001). The mean peak expiratory flow among garri factory workers was significantly lower than that of the controls; 268.25 ± 86.20 versus 349.04 ± 97.21 (L/min) (P < 0.001), likewise the mean forced vital capacity (FVC) (litres) and forced expiratory volume (FEV1) (litres) of garri factory workers and controls were significantly lower than those of the controls; 2.55 ± 1.07 versus 2.87 ± 0.79 (P < 0.001) and 2.00 ± 0.76 versus 2.41 ± 0.83 (P < 0.001) with FEV1/FVC ratio of 0.82 ± 0.16 versus 0.87 ± 0.06 (P < 0.001), respectively. The restrictive pattern of ventilatory functional abnormality was predominant among garri factory workers, 92 (26.2%). Sixty-two (17.7%) and 8 (2.3%) of garri factory workers had an obstructive and mixed pattern of ventilatory function abnormalities, respectively. CONCLUSION: Garri processing workers had significant ventilatory function impairment. Preventive strategies should be encouraged to reduce occupational hazards associated with garri processing in Nigeria.

Spatiotemporal distributions of polycyclic aromatic hydrocarbons close to a typical medical waste incinerator.

Environmental contaminations by polycyclic aromatic hydrocarbons (PAHs) especially from incinerators occur subtly, and PAH contribution from this source is underestimated. However, as environmental PAH concentrations build up, this may be a serious concern around the incinerator vicinity due to the potential consequences of PAHs on ecosystems and human health. Thus, the contribution of selected (12) PAHs from the Obafemi Awolowo University Teaching Hospital medical waste incinerator (or source, HWI_0) was determined by sampling stack gas and ambient air around incinerator vicinity from June 2014 to May 2015. Results showed that the 12 PAH source (HWI_0) concentrations were in the range of NA (for phenanthrene, pyrene, anthracene, benz[e]acephenanthrylene, and indeno[2,1-b]chromene) to 10.9 ng/m3 (pyrelene) and generally higher than the receptor points (hospital waste incinerators (HWIs)). The average total PAH concentrations per month at HWI_0 and the receptors-HWI_1, HWI_2, HWI_3, HWI_4 and HWI_5-were 73.0 ± 27.9, 60.4 ± 30.8, 42.5 ± 23.6, 38.7 ± 21.9, 35.0 ± 27.2, and 39.2 ± 22.9 ng/m3, respectively. These results and multivariate receptor model analysis indicated high correlations between source PAH contributions and the receptor points. The PAH concentrations in the dry season were higher than the wet season suggesting that hydrological condition affects ambient PAH concentrations. The average PAH concentrations in the HWIs as well as the cumulative exposure concentrations observed throughout the period are of major health concern because PAH concentrations detected are several times higher than both the European Union standard and the WHO guideline level.