As part of a global effort to bring attention to corrosion-related issues, the World Corrosion Organization (WCO) (New York, New York, USA) recently acknowledged April 24, 2021 as Corrosion Awareness Day. According to the WCO, an estimated $2.5 trillion USD is spent annually on corrosion costs, which the organization says “[reflects] in part many decision-makers in industry and government not fully understanding the consequences of corrosion and how critical it is to control it.”
To commemorate Corrosion Awareness Day, researchers and students at Western University (London, Ontario, Canada) produced a video that outline some of the major corrosion issues facing Canadians in particular, but that could be generally applicable to people living all around the world.
One such issue is distributing drinking water through lead pipes, which are still common in Canada and around the world. Lead pipes are susceptible to corrosion due to the ions present in water, which can result in toxic amounts of lead being released into drinking water and cause a variety of health issues.
“Cancer is a very good example, as 75 percent of it is caused by lifestyle factors or environmental factors that can be avoided,” says Yolanda Hedberg, a Canada Research Chair in Corrosion Science at Western University. “And metal exposure, due to corrosion, is one of these issues.” Hedberg adds that a variety of health issues can stem from lead ingestion, including reproductive toxicity, anemia, and kidney and brain damage.
While some homeowners had the financial resources to replace their lead pipes with specialized plastic and copper pipes, lead pipes remain in many homes and buildings, particularly older ones. For instance, a 2016 report found that that more than 200 homes in London, Ontario had lead pipes replaced, but estimates suggest that about 4,350 homes were still fully serviced with lead pipes.
“Our workplaces and home environments are causing a lot of cancer. And sadly, metal exposure is usually affecting people disproportionately in terms of socio-economic status,” says Hedberg. “For example, people who can’t afford to get the new materials to replace corroded pipes usually get a higher exposure. They also more commonly work in occupations where you have chemical exposures. Indigenous reserves also, historically, have very high contamination rates with different metals.”
Another problematic source of corrosion is the long-term storage of Canada’s used nuclear fuel. About 15 percent of Canada’s electricity is generated from fuel bundles that are harnessed in nuclear reactors. Once these fuel bundles are used up, they must be safely stored until they are no longer radioactive. Given that there are about 2.9 million used fuel bundles in Canada alone—enough fill eight hockey rinks from the ice to the top of the boards—storing them is a considerable challenge, especially since it takes approximately 100,000 years for their radioactivity to diminish to the level of natural uranium.
“We need a long-term storage solution,” says Jamie Noël, chemistry professor at Western University.
As Noël notes, the Nuclear Waste Management Organization in Canada has recommended commissioning a deep geological repository that would store used fuel in copper-coated and carbon steel reinforced canisters. These cannisters would then be placed in bentonite clay boxes and buried 500 meters below ground in Canada’s bedrock. Noël’s research group is currently studying the corrosion of these canisters to ensure that Canada’s groundwaters do not reach the fuel bundles, thereby contaminating the surrounding environment.
Finally, researchers at Western University and elsewhere are looking into the effects of salt on steel-reinforced concrete used in roads and highways. Road salt is used during the winter months to lower the melting point of ice so that roads are less slippery.
However, according to Western University postdoctoral associate Arthur Situm, these road salts present a few drawbacks: for one, salt corrodes the metal parts in vehicles, and for another, ices melt and mixes with the salt to create a salty liquid that seeps into the steel-reinforced concrete of bridges. This accelerates corrosion of the steel rebar within the bridge and causes to the surrounding concrete to break off, resulting in a process known as spalling.
One example of spalling that Situm cites is the Garniner Expressway in Toronto. In 2012, multiple sections of concrete fell onto the round and even struck a car, which city officials attributed to a backlog of more than $500 million in needed corrosion-related repairs.
Source: Western News, https://news.westernu.ca.