Ilmansaasteiden terveysvaikutukset

Ilmansaasteet lisäävät ihmisten sairastumisia mm. hengitystie-, sydän- ja verisuonitauteihin sekä aiheuttavat ennenaikaisia kuolemia. Ilmansaasteet ovat suuri ongelma globaalisti ja Euroopassa. Tässä työssä arvioidaan tilannetta Suomen kannalta. Työssä arvioitiin seuraavien ilmansaasteiden (PM2,5, PM10 ja sen sisältämä As, Cd, Ni, Pb ja BaP, sekä kaasumaiset NO2, O3, SO2, CO, C6H6, TRS) terveysvaikutukset tautitaakka-käsitteen avulla. Vuoden 2013 tilanteessa tautitaakan arvioitiin olevan 33 000 DALYa, josta menetettyjen elinvuosien osuus on noin 80 % ja sairastavuuden 20 %. Tämä vastaa noin 1600 ennenaikaista kuolemantapausta, joissa elinikä lyhenee noin 16 vuottta. Koko väestölle keskimääräistettynä jokaisen suomalaisen eliniän odote lyhenee noin 5,3 kk ilmansaasteiden takia. Terveyshaittojen pääaiheuttajia ovat pienhiukkaset (64 %), hiukkaset (13 %), typpidioksidi (13%), otsoni (2 %). Arviota täydentävien hiukkasten sisältämien raskasmetallien, PAH-yhdisteiden ja kaasumaisten ilmansaasteiden osuus noin 8 %. Ilmansaasteiden aiheuttamien terveyshaittojen vähentämiseksi tulisi ennen kaikkea vähentää pienhiukkaspäästöjä. Kotimaisin toimin voidaan vähentää liikenteen ja pienpolton päästöjä

Residential wood combustion in Finland : PM2.5 emissions and health impacts with and without abatement measures

Exposure to fine particles in ambient air has been estimated to be one of the leading environmental health risks in Finland. Residential wood combustion is the largest domestic source of fine particles, and there is increasing political interest in finding feasible measures to reduce those emissions. In this paper, we present the PM2.5 emissions from residential wood combustion in Finland, as well as the resulting concentrations. We used population-weighed concentrations in a 250 × 250 m grid as population exposure estimates, with which we calculated the disease burden of the emissions. Compared to a projected baseline scenario, we studied the effect of chosen reduction measures in several abatement scenarios. In 2015, the resulting annual average concentrations were between 0.5 and 2 µg/m3 in the proximity of most cities, and disease burden attributable to residential wood combustion was estimated to be 3400 disability-adjusted life years (DALY) and 200 deaths. Disease burden decreased by 8% in the 2030 baseline scenario and by an additional 63% in the maximum feasible reduction scenario. Informational campaigns and improvement of the sauna stove stock were assessed to be the most feasible abatement measures to be implemented in national air quality policies

Influence of spatial resolution on population PM2.5 exposure and health impacts

Health effect estimates depend on the methods of evaluating exposures. Due to non-linearities in the exposure-response relationships, both the predicted mean exposures as well as its spatial variability are significant. The aim of this work is to systematically quantify the impact of the spatial resolution on population-weighted mean concentration (PWC), its variance, and mortality attributable to fine particulate matter (PM2.5) exposure in Finland in 2015. The atmospheric chemical transport model SILAM was used to estimate the ambient air PM2.5 concentrations at 0.02° longitudinal × 0.01° latitudinal resolution (ca. 1 km), including both the national PM2.5 emissions and the long-range transport. The decision-support model FRES source-receptor matrices applied at 250-m resolution was used to model the ambient air concentrations of primary fine particulate matter (PPM2.5) from local and regional sources up to 10 km and 20 km distances. Numerical averaging of population and concentrations was used to produce the results for coarser resolutions. Population-weighted PM2.5 concentration was 11% lower at a resolution of 50 km, compared with the corresponding computations at a resolution of 1 km. However, considering only the national emissions, the influences of spatial averaging were substantially larger. The average population-weighted local PPM2.5 concentration originated from Finnish sources was 70% lower at a resolution of 50 km, compared with the corresponding result obtained using a resolution of 250 m. The sensitivity to spatial averaging, between the finest 250-m and the coarsest 50-km resolution, was highest for the emissions of PPM2.5 originated from national vehicular traffic (about 80% decrease) and lowest for the national residential combustion (60% decrease). Exposure estimates in urban areas were more sensitive to the changes of model resolution (14% and 74% decrease for PM2.5 and local PPM2.5, respectively), compared with estimates in rural areas (2% decrease for PM2.5 and 36% decrease for PPM2.5). We conclude that for the evaluation of the health impacts of air pollution, the resolution of the model computations is an important factor, which can potentially influence the predicted health impacts by tens of percent or more, especially when assessing the impacts of national emissions