Dataset of trace elements concentrations in snow samples collected in Jelgava City (Latvia) in December 2020

The data set provided in this article consist of two repeated data sets of chemical elements concentrations in snow samples. The snow samples were collected in Jelgava city at December 15th with 5 day exposition time. Snow samples were collected in 59 monitoring points in Jelgava city and in one sample in rural area monitoring point as control. The collected snow samples were melted, acidified with HNO3 and analysed with ICP-MS. The samples were analysed Aluminium (Al), Silicon (Si), Chrome (Cr), Manganese (Mn), Iron (Fe), Nickel (Ni), Copper (Cu), Zinc (Zn), Arsenic (As), Molybdenum (Mo), Cadmium (Cd), Barium (Ba), Tungsten (W), Lead (Pb). The collected data are with fundamental scientific value and can be applied only for local data analysis. Data set is useful for local city air quality research work and for evaluation not only local urban impact but in future evaluate city green infrastructure impact on air quality and evaluation of air pollution mitigation measures efficiency.


Specifications
Atmospheric Science Specific subject area The urban air quality Type of data

Value of the Data
• The urban air pollution is related with increasing human health risks. The knowledge about chemical elements distribution in urban areas helps to develop and improve city infrastructure. • The data could be very useful for local authorities as well as can be used for fundamental research where urban air pollution issues are investigated. • The information of air pollution is very useful with temporal distance where by repeating of experiment it is possible to evaluate mitigation measures. • The collected data can be used to evaluate point-source and nonpoint-source, pollution impact on air quality. • The multidisciplinary research of dust and chemical elements long distance transport in future will be possible if data in this article are included in models with point source pollution [1] and distribution of chemical elements in catchment areas [2] .

Data Description
The raw data of chemical elements concentrations Al, Si, Cr, Mn, Fe, Ni, Cu, Zn, As, Mo, Cd, Ba, W, Pb in snow samples collected December 2020 are presented in Table S. The unit of concentrations measurement is microgram per liter (μg/l). In Table S first column is ID number of monitoring points. Second and third column represents coordinates of monitoring point. The fourth column represents snow sample number for each monitoring point.

Experimental Design, Materials and Methods
The location of data collection area is presented in Fig. 1 . The Jelgava city with ∼ 57 0 0 0 inhabitants is located in central part of Latvia. The sampling areas were selected with aim to monitor transport corridors in Jelgava city. The 59 sampling points were in Jelgava city and one reference point was in rural area at SW from Jelgava city.
The first snow event in Jelgava was at 11 th of December 2020. The snow samples were collected at 15 th of December 2020. Snow deposition period was 5 days [4] . This period represent normal city life where transport flow is more active during week days end, less intensive during weekends. The air temperature, precipitations wind direction and wind speed [5] during deposition period is presented in Fig. 2 .  The three snow samples in each monitoring point were collected 5 meters from road [6] edge using measuring tape and 25 cm diameter steel ring covered with teflon Fig. 3 . The snow depth was from 7 cm to 19 cm. The snow from ring were collected using disposable dust free nitrile gloves. All snow cover profile from sampling ring were collected in plastic containers and immediately transported to laboratory. The melted snow water was from 378 ml till 436 ml. Deionised water (Millipore, EC < 0.055 μS/cm) was used as blank solution. Calibration graph was constructed in concentration diapason from 0.1 μg/L to 100 μg/L. 10 μg/L internal standard mix solution of Bi, Ge, In, Sc, Tb, Y and Li was used as internal standard for system stability control. One standard solution was introduced into system after every ten samples to verify stability of measurements. Measurements were made in MS/MS configuration using He as collision gas (He flow -5 mL/min). The instrumental parameters of ICPMS were set as follows: RF power -1550 W, sampling depth -8 mm, auxiliary gas flow -0.90 mL/min, plasma gas flow -15 L/min.

Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships which have or could be perceived to have influenced the work reported in this article.

Acknowledgments
The snow sampling were funded by Latvia University of Life Sciences and Tecnologies and analysis of chemical elements in samples were funded by University of Latvia.

Supplementary Materials
Supplementary material associated with this article can be found in the online version at doi: 10.1016/j.dib.2021.107300 .