A McMaster researcher is warning that Hamilton households are susceptible to the lead poisoning problems that have afflicted drinking water in Flint, Michigan and other US cities over the past two years. The threat is especially serious for children and pregnant mothers living in buildings constructed before 1960 when lead water pipes were the construction norm, but lead-containing soldering joints continued to be used in some homes until the late 1980s.
In a public lecture last week, Dr Sarah Dickson and two colleagues from the United Nations University tackled the question of “why did Flint happen and can it happen here” and related issues of world water security that have implications for Canadians. Dickson detailed the history of the Flint crisis which has resulted in negligence charges against several government officials, but she also stressed that “there is no safe level of lead to consume” and that Ontario doesn’t use an appropriate sampling protocol to determine actual lead levels in municipal water supplies.
“We have this 15 parts per billion (ppb) actionable limit, but in fact, there isn’t a safe level and so our protocol treatment should insist that we minimize it so we shouldn’t say get it down to 15 and stop,” Dickson stated. “It needs to be as low as possible and the law should require us to do everything we can to get there and then obviously mandate corrective actions when exceedences occur. There needs to be better monitoring programs. All of these things are as true here as they were in Flint.”
Lead has long been known as a neurotoxin and is linked to heart and kidney problems and other health impacts, but it is also strongly connected to negative social behaviours such as increased aggression and violence in adults exposed during childhood. A heavily-documented review by British columnist George Monbiot found that violent crime in many jurisdictions peaked 20 years after bans on leaded gas and other protective measures.
“One paper found, after 15 variables had been taken into account, a four-fold increase in homicides in US counties with the highest lead pollution,” reports Monbiot. “Another discovered that lead levels appeared to explain 90% of the difference in rates of aggravated assault between US cities.”
Hamilton council looked at household lead levels after a scare in London, Ontario in 2007. Sampling of homes that year and into 2008 found nearly a third exceeded the 10 ppb provincial maximum. An accompanying map, not surprisingly, indicates they were almost all north of Mohawk – the portion of the city developed before 1960.
The city installed lead pipes until the 1950s and now offers a replacement program for the pipe connected to homes that includes a loan of up to $2500 to homeowners to cover the portion of the pipe that is inside their property line. Once the homeowner replaces their feed in line, the city says it will do the same for its portion.
The city’s program stresses that loans are only for the feed-in line and are not available “to cover any other associated costs (e.g. the costs of relocating internal plumbing)”. Dickson stresses, however, that internal lead pipes and fixtures also must be replaced at the same time or the contamination will actually be worsened.
“It is estimated that there are 20,000 homes with lead water service pipes that are connected to the city’s water distribution system,” says the city’s website. “Based on the current replacement rate and uptake from residents, it will take 25 to 40 years to remove all of the lead water lines in Hamilton.”
The Flint crisis was exacerbated by a city cost-saving decision to switch their water source to the Flint River which significantly increased corrosion of lead pipes. Hamilton has a $5 million plan to add an anti-corrosion agent (orthophosphate) to treated water starting in 2018 to “help protect Hamilton citizens from the potential health impacts of lead.”
Anti-corrosion measures are required by provincial legislation that was adopted nearly a decade ago. The city’s plan is to remove the additional phosphate after it returns in the form of household sewage to minimize impacts on the harbour.