<b>Ambient Air Pollutant Trends in Zurich (2015–2019) and the 2017 Uranium–Arsenic Exposure Event</b>

TL;DRThree files (Excel, PDF, PNG) present 14-day moving-average time series for ten air-pollutant metrics (Jan 2015–Jun 2019), a summary table of four winter “burdens,” and a multi-page PDF of plots. The focus is on the extreme Dec 2016–Mar 2017 episode and its link to a documented spike in urinary U/As (https://doi.org/10.6084/m9.figshare.27435639.v5).AbstractBetween January 2015 and mid-2019, continuous monitoring of PM₁₀, PM₂.₅, PM₁₀₋₂.₅, elemental carbon (EC), CO, NO₂, SO₂, and their ratios (EC/PM₂.₅, NO₂/SO₂, PM₂.₅/PM₁₀₋₂.₅) revealed an exceptional pollution episode in winter 2016–17. This period immediately preceded a rise in urinary uranium and arsenic in local patients¹. We provide smoothed time series, a qualitative “winter-burden” comparison across four Dec–Mar intervals, and a hypothesis on long-range transport of U/As-bearing fly ash.Methods &amp; Data Sources<b>Measurements:</b> Daily concentrations of PM₁₀, PM₂.₅, PM₁₀₋₂.₅, EC, CO, NO₂, SO₂<b>Derived Ratios:</b> EC/PM₂.₅, NO₂/SO₂, PM₂.₅/PM₁₀₋₂.₅<b>Smoothing:</b> 14-day moving averages (4-week window for PM₂.₅/PM₁₀₋₂.₅)<b>Comparative Winters:</b>Dec 2015–Mar 2016Dec 2016–Mar 2017 (“U/As precursor”)Dec 2017–Mar 2018Dec 2018–Mar 2019<b>Missing-Data Handling:</b> See related dataset for PM₂.₅ imputation (gradient-boosted regression) and other pollutants: https://doi.org/10.6084/m9.figshare.28830278.v14<b>Source:</b> Bundesamt für Umwelt (BAFU) Ambient Air Quality DatabaseFiles Included (3 total)<b>Compare_AP_2015–2019.xlsx</b> (1 file)Sheets: Imputed_AP_Data_Zurich, NO2_SO2_Zurich, AP_Time_GraphsContains raw &amp; 14-day–smoothed time series, plus calculated ratios (Jan 2015–Jun 2019).<b>air_pollutants_timeseries_uploaded.pdf</b> (1 file)10-page PDF (one panel per pollutant/ratio) showing 14-day averages with Jan 1 ticks.<b>Table 1.png</b> (1 file)High-res “Qualitative Comparison of Winter Pollutant Burdens” table (Low ↔ Very High).Key Findings<b>Finest Particles Dominate:</b> PM₂.₅ and PM₁₀ peaked highest in Jan–Mar 2017; PM₂.₅/PM₁₀₋₂.₅ ratio confirms fine-aerosol supremacy.<b>Combustion Tracers at Max:</b> EC, CO, NO₂ all reached their 2015–19 maxima in early 2017; NO₂/SO₂ ratio soared.<b>EC Fraction Nuance:</b> Despite high EC mass, EC/PM₂.₅ fraction was slightly lower than in winter 2015–16, indicating a large non-EC fine component.<b>SO₂ &amp; Coarse PM Steady:</b> SO₂ was moderate (below winter 2015–16), and PM₁₀₋₂.₅ showed no unique surge.<b>U/As Link:</b> The Dec 2016–Mar 2017 pollution profile aligns with inhalation of U/As-bearing fly ash, matching the patient‐urine spike¹.ReferencesCarmine, T. C. (2024). <i>The Uranium Episode (March–May 2017) in Temporal Context: Associations with CEMET Uranium, Aluminum, and Local PM₁₀ Exposure (2016–2019).</i> Figshare. https://doi.org/10.6084/m9.figshare.27435639.v5PM₂.₅ imputation &amp; missing-data methods: https://doi.org/10.6084/m9.figshare.28830278.v14<i>Please cite this repository and associated DOIs when reusing data or figures.</i>