Winter increases pollution drastically. Keeping this in mind, the Massachusetts environmental officials are weighing whether to let four gas-powered plants switch to dirtier oil up to 50 percent more. They wish to repel shortages of natural gas and blackouts. With this concern, the State regulations restrict the number of days the four gas-powered plants are allowed to burn oil. This plan would allow air-pollution emissions to rise to higher federal limits. That means the four plants could burn oil anywhere from 6 to 32 more days, i.e. 20 to 50 percent more this winter, if their owners choose. The move would lead to 50 more tons of particulate matter, or soot, being emitted annually, and also a 1 percent statewide increase in smelly, smog-forming sulfur dioxide from electric generation. These changes in the air quality may bother residents, especially those with asthma and lung disease.