Lead Contamination in Flint, Michigan Drinking Water
Eric Roy, Ph.D. | Scientific Founder
I wanted to take a make our readers aware of a largely unreported disaster that is underway in Flint, Michigan. The residents of Flint, MI are being poisoned by lead in their tap water because the municipality messed up... big time. In this post, I'll focus on the science behind lead contamination, the facts (as we know it) of what happened in Flint, and touch upon another time in the recent past when a similar thing happened.
All water has impurities in it. Most impurities are harmless (e.g. dissolved oxygen, various minerals), some are harmful (e.g. lead, arsenic, mercury).
Impurities typically enter tap water in 3 ways:
1. Some are found in the source water (e.g. naturally occurring minerals)
2. Some are deliberately added as part of the treatment process (e.g. chlorine)
3. Some are picked up along the way from the treatment facility to the tap.
Lead is almost never found in source water at dangerous levels, and nobody deliberately adds lead to their water supply, because it's toxic. Lead can, however, be be introduced to tap water as it flows from the treatment facility to the tap.
How is Flint’s tap water picking up lead in transit?
It’s pretty straightforward: Nearly all homes with plumbing installed before the 1986 use lead-containing solder to join copper pipes. Lead can also be found in residential plumbing fixtures manufactured before 1998. Additionally, some older homes use lead service line pipes to connect water mains to homes. Proper water quality testing (e.g. pH, chloride, toxic metals) and corrosion control practices (e.g. monitoring chloride levels, maintaining a slightly alkaline pH, adding corrosion inhibitors) are what keep residents with older plumbing and service connections safe from lead contamination. This is not unique to Flint. Unfortunately, it's not always done correctly, and residents suffer.
In Flint, as well as other places where high lead levels have leached into municipal tap water (e.g. Washington, DC in the early 2000’s), monitoring and corrosion control measures failed, which allowed lead to dissolve from pipes/fittings/fixtures and poison the residents.
What changed in Flint to cause the problem?
In 2014, Flint stopped buying its tap water from Detroit (which has proper corrosion control measures in place), and began collecting their water from the Flint River as part of a plan to switch to a different water supply. During the changeover process, the municipality failed to implement effective corrosion control measures, and the corrosive water allowed lead to leach from lead-containing plumbing. Because proper water quality monitoring procedures were not in place, the Lead problem was not widely discovered until recently.
Flint has announced that it will resume buying water from Detroit in the next 2 weeks, which gets its raw water from Lake Huron and has proper monitoring and corrosion control measures in place. This is a great first step, but it's important that Flint keeps monitoring their water for lead, because the pipes can continue to leach lead while the corrossion control measures build up the protective layer on the inside of the pipes. The length of time this takes will depend on the degree of corrosion, and whether or not Flint's water will have "boosters" of the anti corrosion chemicals.
Until lead levels drop, residents are being urged to use a quality water filtration system that effectively removes lead. Contrary to some of the information out on the internet... boiling waterbefore use does NOT decrease the amount of lead. It is critical that Flint residents use a filter that effectively removes lead, and also changes the cartridges on a regular basis. I would expect that the filtration capacity (in gallons) for lead would be much lower than the manufacturer claims, because the gallon capacity ratings were determined using water with much lower lead concentrations than what is currently being measured in Flint.
Even though there is a plan moving forward, this type of incident almost certainly caused harm to some residents Flint, and the areas most affected by it were probably homes with older plumbing. Even though lead contamination is odorless and tasteless, it has devastating effects on human health. Since Flint began using the Flint River as a water source, numerous children have tested positive for high levels of lead in blood, and a number of schools have recently shut down water fountains due to high lead levels. When a similar lead contamination issue occurred in Washington DC between 2001-2004, stillbirths shot up during the affected years (Edwards, 2013). As was the case in Washington, DC, the full extent of harm likely will not be realized for several years.
*** Update June 2016: We are getting a lot of questions from Flint residents about what to do now. The message that we want to communicate to people in Flint is that you now have a world leader in Mark Edwards actively working with the city to help fix the problem. There is quite literally no person on earth with more credibility than Dr. Edwards on this topic, and noone with a better track for helping people who have been affected by this sort of disaster. Please listen to him with open ears. He will not lie to you. There are a lot of far less credible people who are looking to elevate their status by saying things that will resonate with residents. Please do not listen to them. This problem will take longer to fix than it took to create, but understand that you now have the top expert on earth working on the problem.
_M. Edwards. Fetal death and reduced birth rates associated with exposure to lead-contaminated drinking water. Environmental Science & Technology. Published online December 9, 2013. doi: 10.1021/es4034952.
Other Great Articles From Water Smarts Magazine:
Tap Water Chlorination: The Good, The Bad, The Unknown
Fluoride in Municipal Tap Water: What You Need To Know
Disinfection Byproducts: What You Need To Know
- Water Experts