The road is less polluted than your kitchen
Commuting by bus in Delhi exposes you to the lowest concentrations of fine-particle pollutants called black carbon, or soot, as compared with other modes of transport -even lower than the exposure you are likely to get travelling in a car, a study reveals.
The study, published in Elsevier journal on environmental research, assessed people’s personal exposure to pollution in Delhi. For outdoor exposure, it considered commuters in cars, buses and autorickshaws.
Travellers in autorickshaws were found to be at the highest risk of inhaling soot, a product of incomplete fuel combustion with harmful impacts on the lungs and heart.
“Exposure to particles is lower in cars than on two-wheelers and autorickshaws, but driving a car with open windows could lead to similar levels (of exposure) as in an auto,” said Pallavi Pant, lead author of the study . Pant admitted that the findings on exposure to pollution inside a car was surprising. “From the current analyses, black carbon concentrations in buses seem to be lower in comparison to other modes, but more research is needed to confirm this, both in Delhi and other cities. AC use can help reduce exposure in cars,” she said.
It’s not only being out on the roads that exposes you to respirable pollution particles. Your home, especially the kitchen, could be enveloping you in PM2.5 pollutants too, the study said.
It found high exposure to PM 2.5 pollutants in indoor activities such as cleaning or cooking. However, the nature of pollution indoors differs from that outdoors. According to Pant, exhaust emissions on the roads could be far more toxic than say pollutants arising from cooking or cleaning.”Cooking emissions often comprise ultrafine particles that can be harmful,” Pant said. “Research on ultrafine particles is ongoing, but so far we know they can have several adverse health effects.” Pant suggested opening the windows and using exhaust fans during cooking or cleaning to avoid accumulation of such pollutants.
Buses, because they use CNG as fuel in Delhi, do not emit soot and are safer. Also, bus passengers sit at an elevated height compared with autorickshaws and cars and avoid the denser pollution layer near the road surface. In cities where buses run on diesel, they may , however, show higher levels of black carbon. An in-depth analysis is required to confirm this.
The authors, from the University of Massachusetts, Amherst, IIT Delhi and University of Washington, have suggested more studies on in-vehicle exposure. “Future studies should look at in-vehicle exposure with respect to land use and traffic characteristics, and personal exposure data should be used as an input for land use zoning and urban transportation planning,” the study concluded.
The researchers worked with healthy volunteers, men and women, aged 18 to 60 years. Their individual exposure to pollution was sampled using portable sampling devices. Commute exposure was recorded on a 22km sampling route, including a section of the busy Mathura Road-National Highway 2, during peak hours (8-10am and 6-8pm) and off peak times (12 noon-2pm). Most volunteers were non-smokers and all used LPG as cooking medium at home. They spent 40-90 minutes commuting daily and 8 to 10 hours at work.
The study also reported that pollution risk is higher in winter than in summer. “The pattern for personal exposure to particles is similar to ambient air quality, and can be as much as six times higher than the national air quality standard in winter,” said Pant. Commuting by bus in Delhi exposes you to the lowest concentrations of fine-particle pollutants called black carbon, or soot, as compared with other modes of transport -even lower than the exposure you are likely to get travelling in a car, a study reveals. Commuting by bus in Delhi exposes you to the lowest concentrations of fine-particle pollutants called black carbon, or soot, as compared with other modes of transport -even lower than the exposure you are likely to get travelling in a car, a study reveals.
