tailieunhanh - Using lichen as bioindicator of air pollution: Acid deposition Monitoring and Assessment Third country Training

The different sources of potential confounding in time series studies of air pollution and mortality can be broadly classified as either measured or unmeasured. Important measured confounders include weather variables such as temperature and dewpoint temperature. Daily temperature measurements are readily available for metropolitan areas in the USA and numer- ous studies have demonstrated a relationship between temperature and mortality which is gen- erally positive for warm summer days and negative for cold winter days (. Curriero et al. (2002)). One approach to adjusting for confounding by temperature is to include non-linear functions of current and previous day temperature (and dewpoint) in the model (Schwartz, 1994a; Kelsall et. | t Tansf m HO O H2O O2 SO2 O2 2 NOx Ecosystem Plant Source Human NOx SO Animal th way of pollutants in the atmosphere HSO HNO Sink 1 Brief history of using lichens as bioindicator of air pollution Other air pollutants NOx O3 heavy metals HF organic pollutants caused disappearance of lichens from cities industrial areas. In 1866 it was noted that lichens disappeared from Jardin de Luxembourg near Paris. Smoke from burning of coal was the course. SO2 from burning coal damaged to lichens. Lichens have been used as bioindicator of air pollution world wide 2 Lichens depend on atmospheric moisture rain fog dew for growth Pollutants in the air dissolved in atmospheric water are damaged to lichens Lichens are sensitive to air pollution Ramalina farinacea