Distribution of Iron in Dust Near Streets: Case Study Jelgava City

The world's urban population is projected to grow to 68% by 2050. According to statistics, 68% of the country's population already lives in Latvia in 2022. Much of the air pollution research in the city is focused on researching highways and streets of very intensive traffic. Small and medium-sized cities with their infrastructure remain unexplored. The population of cities of different sizes is growing every year, so it is important to understand the prevalence of pollution along the streets in small and medium-sized cities, as this pollution has a direct impact on the health of the city population. Snow and stored dust are good matrices to assess the extent of air pollution and metals in urban areas. It should also be stressed that the number of cars in cities is increasing, while the age of the car fleet remains increasing. The aim of the study is to find out how iron is distributed at different distances from the street section in Jelgava city research facilities. Snow samples were collected at 3 monitoring points with a distance of 1 m, 50 m, and 100 m to each side of the street. Snow samples were melted, acidified, filtered, and measured with ICP-OES spectrometer. For data analysis, descriptive statistics, the Kruskal-Wallis test, and the Steel-Dwass-Critchlow-Fligner procedure were used. In all monitoring points, iron pollution in air at 1 m is statistically significantly higher than at 50 m and 100 m (p-value 0.018; and 0.011), which directly indicates the impact of cars on air quality close to the streets. At the monitoring point located on Riga Street, the iron concentration at 1 m distance is 10.9 mg/l and at 100 m 0.33 mg/l. The data obtained can be used when designing streets and conducting urban planning.