Not only is biomass not a good source of power, claims a 2007 paper presented at the European Aerosol Conference, it's also not a healthy alternative to coal. The paper claimed that particulate matter (particles, such as dust, dirt, soot or smoke) was actually higher for a 7 megawatt wood gasification plant than it was for a large coal-fired power station.
And particulate matter (PM) is very dangerous. The EPA asserts that it can cause asthma, chronic bronchitis and even premature death in people with heart or lung disease. On the environmental side, PM can change the nutrient values in water bodies, turning streams and lakes acidic.
“At every turn biomass is a complete and utter train wreck,” added [Jeff] Gibbs. “Chopping up and burning whole trees will not conquer global warming, it will only exacerbate the problem beyond the point of no return.”