Chapter 7 - Atmospheric pollution and solar ultraviolet radiation in Asia

Abstract

This chapter deals with atmospheric pollution, particularly the aerosol optical depth (AOD) and its impact on ultraviolet radiation flux reaching the Earth's surface, and its subsequent effect on vitamin D levels observed in the Asian region. It begins with the mean distribution during the last 16 years (2001–2016) of AOD, UVA, and UVB fluxes over Asia along with their trends on a 1°×1° grid scale. The Clouds and Earth Radiant Energy System (CERES) is the main source of data supported by data from MISR. High AOD values over Asia are well anticorrelated with the UVA and UVB fluxes reaching the surface. The reducing trend in UVB due to an increasing trend in AOD is a matter of concern, as UVB has a direct relation with the level of vitamin D prevalent in the Asian population, particularly in the South, Southeast Asian region. The accelerated economic development during the last two decades in Asia has led to an enhancement in AOD leading to a decrease in UVB reaching the surface and possibly reducing the production of vitamin D on a huge population in the region. Further targeted studies are however required to quantify the amount of reduction in vitamin D due to enhanced air pollution and AOD.