Wood smoke residential heaters pose health risk
As the heating season draws near, wood smoke from outdoor wood-fired boilers (OWBs) and other wood heaters will lead to health and nuisance complaints across the state.
The Wisconsin Department of Health Services (DHS) reports that homeowners who are chronically exposed to smoke often complain of adverse health effects such as asthma, respiratory irritation, sinus problems or headaches. People with lung or heart conditions, children and the elderly are even more at risk from exposure to smoke.
Wisconsin is a leader in the number of operating OWBs, and in the absence of regulation, this trend is expected to continue. Several features make OWBs a popular alternative heating source: the fire hazard is outside of the building being heated; wood storage and handling takes place outside; and wood is a renewable fuel source that may be less expensive than gas, oil or electricity.
However, there are significant disadvantages to using an OWB for home heating. “When OWBs are improperly located or operated, or a large number are located in a small area, conflicts with neighbors can occur due to excessive wood smoke and related health effects,” said David S. Liebl of UW-Extension’s Solid and Hazardous Waste Education Center.
Strong smoke odors combined with a visible plume indicate the presence of fine particulates and chemicals, such as carbon monoxide and formaldehyde found in wood smoke. When smoke envelops a neighboring house or property, air quality degrades to conditions similar to those that would cause the DNR to issue an air quality advisory for fine particles, according to Liebl. A recent study of wood smoke in Grand Rapids found high levels of fine particle pollution from wood smoke in neighborhoods where OWBs were being used.
What causes excessive OWB smoke? “Installing a stove with a stack that is too short, or at a distance too close to a neighboring building is probably the main reason for exposure to OWB smoke,” said Scott Sanford, rural energy program specialist with UW-Extension. “Poor design, faulty operation or inappropriate fueling practices also can lead to excessive smoke.” For example, operators should only add wood when there is a demand for heat, and only add enough fuel for heating the next eight to 12 hours (or less) to help reduce smoke emissions.
Poor location or weather conditions that prevent smoke from dispersing can also lead to excessive wood smoke. “Neighbors downwind of an OWB may find themselves in the path of frequent smoke plumes,” Liebl said. “As a public health concern, a visible plume, odors and health or nuisance complaints are sufficient to establish an individual’s exposure to OWB emissions.”
While Wisconsin lacks statewide regulation of residential wood smoke, about 200 local municipalities have some type of ordinance regulating wood smoke, making it easier to resolve smoke related conflicts. If a community does not have an ordinance, Liebl and Sanford recommend that those concerned work with their local village, township, city or county officials to develop an OWB/open burning ordinance. Adopting such an ordinance will reduce the likelihood of exposure to OWB emissions, and provide a way to resolve conflicts.
Those dealing with a health or nuisance issue related to OWBs can take these steps:
• Meet with the OWB owner/operator to discuss the exposure problem.
• Check for proper stack height and property line setbacks.
• Review OWB fueling practices with the operator.
• Make sure nothing but clean dry wood is used as fuel (no trash or other materials).
Individuals who are unable to resolve the OWB emission exposure issue may consult their local health department for assistance.