Demolitions' Hidden Cost: Lead Contamination in Neighborhoods
A few months ago, we discussed the environmental benefits of preserving older houses, in The Environmental Benefits Of Historic District.
In today's post, we'll focus on the toxic contamination created when houses are demolished.
When houses are demolished, large amounts of airborne fragments and particulates - which we see as dust - are emitted in the neighborhood. The total radius of this "dust fall" is as much as 900 yards, on a windless day.
Part of this dust is toxic lead. Most houses built before 1978 contain lead-based exterior paint and sometimes interior paint. So long as the paint is intact and undisturbed, the lead is encapsulated and we are not exposed to it.
But when a house is ripped down with heavy equipment, the paint is pulverized into dust and the lead within is released into the air and soil.
Airborne lead from a home demolition can be spread throughout a radius of 190 yards (570 feet, on a windless day).
Every yard and home within 1 to 2 blocks of the demolition is at risk of contamination from the lead dustfall.
Lead exposure is particularly harmful to children.
Lead is a home health and safety hazard that harms a child’s brain, causing lifelong learning and behavior problems.
When lead dust is ingested or inhaled, even in miniscule amounts, it can cause significant and irreversible brain damage as well as other health problems.
Lead dust equivalent of only three granules of sugar can begin to poison a child.
Source: 2014 Wayne State University presentation on demolition-related lead exposure.
Lead dustfall can contaminate neighboring houses through by coating outside surfaces, entering open windows, and contaminating the lawn, soil, and any gardens. Lead contamination persists in soil for many decades.
In our schools, drinking fountains have been closed until the lead-containing plumbing and fixtures can be replaced. When contractors remodel our kitchen, they are required to follow careful procedures to control lead dustfall.
When developers demolish our houses, they are permitted to release toxic lead dust that contaminates dozens of neighboring homes and yards.
Some demolition crews use hoses to completely soak the house before ripping it down. "Wet" demolition can reduce the range of lead dustfall, but still a radius of about 112 yards (336 feet) is at risk of contamination. However, Portland does not require wet demolition, or more advanced lead-abatement procedures. Instead, the pace of demolitions picks up during the dry months of spring and summer.
Portland recently started requiring "deconstruction", but only for houses built before 1916. Most Laurelhurst houses were built after 1916. Deconstruction remains a violent process. After windows, trim, floorboards, and other salable materials are removed, the house's exterior shell - with the lead-based paint - is still demolished.
Demolitions do much harm to our neighborhood. Destroying smaller, less expensive houses; making our neighborhood less attainable for young families, downsizing families, and anyone who is not very high income; reducing our community's diversity; cutting down trees; and exposing our families and especially our children to toxic lead dustfall.
Why should we permit developers to demolish and redevelop our neighborhood? Historic district stops demolitions.
"As home demolitions reach historic levels in Portland, there are no safeguards against lead dust that can be stirred up when older homes are demolished.
It’s an odd oversight. Federal rules dutifully require safety precautions if those same homes are renovated—rules designed to stop property owners and their neighbors from coming into contact with lead, a neurotoxin for which there is no known safe exposure level.
But when the home is torn down? The lead can fly unchecked, potentially creating problems for soil and nearby neighbors."
OPB has also covered the issue, With Few Rules For Home Demolitions, Threat Of Lead Dust Worries Neighbors.
For detailed information on lead hazards from demolitions, see this presentation "Lead And Demolition" by Wayne State University. This study focused on demolitions in Detroit, but the lessons apply equally in Portland; that discussion starts at slide 11.