Does air pollution protect one from UV-B radiation?
Yes, but at a high price. Air pollution is generally undesirable due to the numerous other serious problems associated with it, including respiratory illness, eye irritation, and damage to vegetation. While most of the atmospheric ozone resides in the stratosphere, some ozone is also made in the troposphere by the chemical interactions of pollutants such as nitrogen oxides and hydrocarbons. This tropospheric ozone is a component of the photochemical smog found in many polluted areas. Airborne particles (smoke, dust, sulphate aerosols) can also block UV radiation, but they can also increase the amount of scattered light (haze) and therefore increase the UV exposure of side-facing surfaces (e.g., face, eyes). No single value can be given for the amount of UV-B reduction by pollution, because pollution events tend to be highly variable and local. Comparisons of measurements made in industrialised regions of the Northern Hemisphere (e.g., central Europe) and in very clean locations at simi
