Black Carbon
Context
- Black Carbon has a significant adverse effect on human health and leads to premature mortality, says a new study by Department of Science and Technology.
Note: The health effects in terms of mortality due to BC aerosol exposure have never been evaluated in India.
Findings
- Indo-Gangetic Plain, experiences very high aerosol loading and trace gas concentrations throughout the year due to prevalence of a subsidence zone (sudden sinking of the Earth's surface).
- The region observed decadal increasing trends both in Aerosol Optical Depth and Black Carbon aerosols.
- From 2009 to 2016, correlation between daily all-cause mortality and ambient air quality establish that there is a clear impact of BC aerosols, NO2 and, PM2.5 exposure.
- The effect of pollutants was more prominent for males, age group 5-44 and, in winter.
- The adverse effect of air pollutants was not limited to current day of exposure but can extend as high as up to 5 days (Lag effect).
- Mortality rises linearly with an increase in air pollutants level.
Significance of the study
- The study could help in the estimation of future burden of mortality associated with air pollutants more accurately.
- Inclusion of Black Carbon as a potential health hazard provides a background for more such studies of effects of air pollutants on health.
- This will help government and policy-makers for better planning to mitigate the adversity associated with changing climate-air pollution-health nexus.
Aerosol
- An aerosol is a suspension of fine solid particles or liquid droplets in air or another gas.
- Aerosols can be natural or anthropogenic.
- Examples of natural aerosols are fog or mist, dust, forest exudates and geyser steam.
- Examples of anthropogenic aerosols are particulate air pollutants and smoke.
Black Carbon
- Chemically, black carbon (BC) is a component of fine particulate matter (PM ≤ 2.5 µm).
- It is formed through the incomplete combustion of fossil fuels, biofuel, and biomass.
- Black carbon is a climate forcing agent contributing to global warming.
- It warms the Earth by absorbing sunlight and heating the atmosphere and by reducing albedo when deposited on snow and ice (direct effects) and indirectly by interaction with clouds.
- Black carbon stays in the atmosphere for only several days to weeks
- The IPCC have posited that reducing black carbon is one of the easiest ways to slow down short term global warming.
Aerosol Optical Depth
- Aerosol Optical Depth (AOD) is the measure of aerosols (e.g., urban haze, smoke. particles, desert dust, sea salt) distributed within a column of air from the Earth's surface to the top of the atmosphere.
Source: https://pib.gov.in/PressReleasePage.aspx?PRID=1731444