Publications by authors named "Urmas Horrak"

Risk assessment of pesticide impacts on remote ecosystems makes use of model-estimated degradation in air. Recent studies suggest these degradation rates to be overestimated, questioning current pesticide regulation. Here, we investigated the concentrations of 76 pesticides in Europe at 29 rural, coastal, mountain, and polar sites during the agricultural application season.

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Article Synopsis
  • Factor analysis conducted in Estonia examined air pollutants (NO, NO2, SO2, O3) across 8 monitoring stations, revealing significant impacts from COVID-19 lockdowns, decreased oil-shale energy production, and differences between urban vs. rural areas.
  • A multiple regression analysis aimed to predict ozone levels at the rural station in Tahkuse, showing a strong correlation (0.714) when using data from a nearby station.
  • Predicted ozone levels improved slightly with more data (0.795), but local concentrations of NO and NO2 were poor predictors, suggesting that ozone transport over long distances influences local measurements.
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This global study, which has been coordinated by the World Meteorological Organization Global Atmospheric Watch (WMO/GAW) programme, aims to understand the behaviour of key air pollutant species during the COVID-19 pandemic period of exceptionally low emissions across the globe. We investigated the effects of the differences in both emissions and regional and local meteorology in 2020 compared with the period 2015-2019. By adopting a globally consistent approach, this comprehensive observational analysis focuses on changes in air quality in and around cities across the globe for the following air pollutants PM, PM, PMC (coarse fraction of PM), NO, SO, NOx, CO, O and the total gaseous oxidant (OX = NO + O) during the pre-lockdown, partial lockdown, full lockdown and two relaxation periods spanning from January to September 2020.

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