Water filtration: Lead in the drinking water |
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Lead is a dangerous toxin that accumulates in the environment. Unlike some toxins, it does not break down and become safer over time. A community’s water supply can become poisoned from lead that has accumulated in the soil. Because it used to be added to gasoline, lead particles from car exhaust still contaminate soils near busy roads. However, this is not the usual way lead enters drinking water. Lead is not normally present in water leaving the water treatment plant, but the treated water is able dissolve lead that exists in old household plumbing and pipes that connect homes into the water. Not all homes have lead pipework, but houses older than 1970 are more likely to have plumbing containing lead. The water in some places more readily dissolves lead, so some communities treat their water by adding phosphate, a mineral that reduces the ability of water to dissolve lead. Because hot water dissolves more lead, it is important to use only cold tap water for drinking and cooking. Water that sits for a long time in lead-containing pipes will also dissolve more lead, so running the tap for at least 5 minutes every morning can flush out the water with higher concentrations of lead, although this method does not always work on top floors of apartment buildings. The only reliable way to avoid drinking water contaminated lead used to be removing all the lead-containing pipes in the house. Pregnant Women and Children No level of lead exposure appears to be safe, and it is tasteless and odourless. Lead is especially dangerous for pregnant women and children, whose intelligence can be affected by long term exposure to lead. In 2007, almost 1% of all consumer taps sampled in Scotland showed levels of lead that exceeded the current standards for “safe” water concentrations of this toxic metal. It is important to note that the current safety standards have been reconsidered and are no longer considered acceptable. In 2013, the standard for “safe” levels of lead will be reduced from 25microgram per liter to 10 microgram per liter. The percentage of households with water that exceeds 10 microgram per liter is not known. Besides lower intelligence, children exposed to even very low levels of lead for long periods are more likely to develop attention deficient hyperactivity disorder and antisocial behavior. Pregnant women exposed to lead are at risk for miscarriage, premature birth and giving birth to low birth weight infants and children who suffer from hearing problems and developmental delays. Although adults are less vulnerable to the effects of lead poisoning, exposure appears to increase adult death rates and contribute to mental decline in older people. A Water Filter Protect your family by installing a water filter. Filters can effectively remove lead from your drinking water without the expense of removing lead pipes from your house. References Drinking Water Quality Regulator for Scotland. Report on the results of the survey of analytical performance for the measurement of lead. Available at: http://www.dwqr.org.uk/reports/summary2.pdf. Accessed January 13, 2009. Drinking Water Quality Regulator for Scotland. Drinking water quality in Scotland 2007. Available at: http://www.dwqr.org.uk/reports/DWQ2007.pdf. Accessed January 13, 2009.
Bellinger DC. Very low lead exposures and children’s neurodevelopment. Curr Opin Pediatr. 2008;20:172–17.
Cleveland LM et al. Lead hazards for pregnant women and children. The American Journal of Nursing. 2008;108:40–49.
U.S. Environmental Protection Agency. Actions you can take to reduce lead in drinking water. 1993. Available at: http://www.epa.gov/safewater/lead/lead1.html . Accessed January 13, 2009.
New York State Department of Health. Sources of Lead. 2005. Available at: http://www.health.state.ny.us/environmental/lead/lead_sources.htm. Accessed January 13, 2009. |
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