In news: According to a study in Nature Communications, black carbon particles typically emitted by vehicle exhaust and coal-fired power plants have been detected on the foetus-facing side of placentas.

  • The concentration of particles was highest in the placentas of women most exposed to airborne pollutants in their daily life. 
  • The placenta nourishes a developing fetus and shields it from damaging substances in the mother's bloodstream.
  • There was no evidence of pollution particles in the fetus itself.


Black Carbon

  1. Black carbon is a potent climate-warming component of particulate matter formed by the incomplete combustion of fossil fuels, wood and other fuels. 
  2. Complete combustion turns all carbon in the fuel into carbon dioxide (CO2), but combustion is never complete and CO2, carbon monoxide, volatile organic compounds, and organic carbon and black carbon particles are all formed in the process.
  3. Black carbon is a short-lived climate pollutant with a lifetime of only days to weeks after release in the atmosphere. 
  4. BC is produced both naturally and by human activities as a result of the incomplete combustion of fossil fuels, biofuels, and biomass. 
  5. Primary sources include emissions from diesel engines, cook stoves, wood burning and forest fires. 
  6. It has recently emerged as a major contributor to global climate change, possibly second only to CO2 as the main driver of change. 

Impact on Ecosystem

  • BC particles strongly absorb sunlight and give soot its black color. 
  • Per unit of mass of black carbon’s warming impact on climate is 460-1,500 times stronger than CO2.
  • When suspended in the atmosphere, black carbon contributes to warming by converting incoming solar radiation to heat. 
  • It influences cloud formation and impacts regional circulation and rainfall patterns.
  • When deposited on ice and snow, black carbon and co-emitted particles reduce surface albedo (the ability to reflect sunlight) and heat the surface. 

Impact on Health

  • As a key component of fine particulate matter (PM2.5) air pollution.these particles can penetrate into the deepest regions of the lungs and facilitate the transport of toxic compounds into the bloodstream.
  • PM2.5 has been linked to a number of health impacts including premature death in adults with heart and lung disease, strokes, heart attacks, chronic respiratory disease such as bronchitis, aggravated asthma and other cardio-respiratory symptoms. 
  • It is also responsible for premature deaths of children from acute lower respiratory infections such as pneumonia.