Environment officials in Massachusetts, usa, are considering whether to let four gas-powered plants to switch to dirtier oil, 50 per cent more often, this winter. The state is focusing on these plants as they can switch between gas and oil.

Officials feel this move could stave off natural gas shortages and blackouts in winters. The state's department of environmental protection claims there would be 50 more tonnes of soot emission annually and an increase in smog. The impact on annual pollution might be negligible, but the effect of additional emissions would be felt near the plants' home communities, specially troubling asthma and lung disease patients.