Browsing by Subject "ilmanlaatu"
Now showing items 1-2 of 2
-
(2022)The aim of this thesis is to understand how restrictions and recommendations to limit the spread of Covid-19 pandemic affected air quality in Helsinki from January to September 2020 and examine the health benefits coming from the decreased pollutant levels. During that time many restrictions to people’s movements took place. This caused a decrease in traffic rates which in turn affected air quality. The air pollutants included in this study are nitrogen oxide (NOx), tropospheric ozone (O3) and particulate matter (PM2.5 and PM10). The data was uploaded from SMEAR III -station in Kumpula neighborhood and the results were obtained by comparing concentrations from 2020 to those of 2018-2019. The data were divided into three periods, which were studied separately. The first period was the time before the lockdown (1.1.-17.3.), 2nd period was during the lockdown (18.3.-15.6.), and the 3rd period was after the lockdown (16.6.-30.9.). In addition, the health effects caused by the changes in pollutant concentration were studied with a calculator for financial benefits of emission reductions made by Finnish Environment Institute. The change in NOx concentrations during 2020 compared to 2018-2019 were -36.4 % in 1st period, -26.5 % in 2nd period and +34.1 % in 3rd period. The changes for O3 were +4.8 % (1st period), -8.6 % (2nd period) and -11.6 % (3rd period). PM2.5 concentrations changed -39.4 % (2nd period) and 0.0 % (3rd period) and PM10 concentrations -46.9 % (2nd period) and -14.7 % (3rd period) during 2020 compared to 2018-2019. Decrease of NOx in 1st period caused 2 600 t€/y savings in costs of air pollution related health effects. The changes in PM2.5 and NOx generated savings of 38 000 t€/y during 2nd period and -2 400 t€/y during 3rd period. Even though the pollutant concentrations decreased in most periods, the decrease can’t be explained only by changes in traffic rates and human activities. Other factors contribute air pollutant levels as well, including atypical weather during 2020. The study could be continued by separating the effects of weather, traffic and other contributing factors in changes in air pollutant concentrations.
-
(2023)Due to population growth, urbanization, and increase in life expectancy, the urban population is growing, and by 2050 68% of the global population is expected to live in urban areas. Even though the air quality in urban settings has greatly improved in recent decades due to increased legislation, restriction, and monitoring, the negative health impacts associated with pollutants have not completely diminished. Air quality varies on a local scale due to urban form and function, that creates differences in experienced exposure among individuals. These exposure differences among socio-economic groups have been studied, but no clear consensus has been found, as the results have been very diverse and even contradictory. Therefore, conducting local level studies is important in order to identify local patterns of exposure and to recognize them in urban planning. However, previous literature on the topic in Finnish context is lacking. This thesis studies interpolated air pollutant exposure among one susceptible socio-economic group – the elderly – and aims to identify possible hotspots of both in Helsinki, Finland. The distribution of the elderly and air quality is assessed through Moran’s I calculations. Global Moran’s I is used to assess for spatial autocorrelation, and local Moran’s I is applied to identify local clusters. To further examine the relationship, correlation coefficients are calculated through Spearman’s rank correlation coefficient. According to the results, there is a weak positive correlation between the elderly and air quality, indicating that generally air quality tends to be worse when the number of elderly people increase. However, the relationship is stronger among younger age groups, although the differences between age groups is very small. The exposure was also assessed through overlapping high value clusters, which indicate that elderly clusters in the city center are located in areas with low air quality, while elderly clusters in Lauttasaari and Vuosaari are located in areas with good air quality. Previous studies regarding the relationship between age and air pollution exposure have been contradicting in different cities, and therefore these results provide important knowledge about the problem specifically in the context of Helsinki. Additionally, the results are be observed in the light of the larger discourse around socio-economic status and air pollution, but further studies on the topic are still needed. Including multiple socio-economic variables and the dimension of negative health outcomes would aid in identifying 1) the most important socio-economic factors in the context of negative health outcomes associated with air pollution, and 2) those areas where multiple important socio-economic factors and low air quality are overlapping and therefore might have higher risk for negative health outcomes.
Now showing items 1-2 of 2