By now we have all know about the water crisis in Flint Michigan. Tons of articles have been written discussing the politics surrounding the Lead contaminated water. As a result many misconceptions have arisen, for example; many people assume that when it is said that the water was “corrosive” that, that meant the Flint River water was contaminated with lead already. This however is not the case. What if I told you that water sources such as rivers and lakes can be naturally corrosive? What if I told you that lead is not the only substance in the Flint water that residents should be concerned about?
What is Corrosive water anyway?
When water is said to be corrosive, what we are really talking about is it’s pH (power of hydrogen); whether it is acidic, basic, or neutral. The pH scale goes from 0 to 14, with 0 being most acidic, 14 being most basic, and 7 being neutral. Strong acids are just as corrosive as strong bases. In the preparation of drinking water, pH is important in determining how the water with be treated and in how its corrosively will be controlled. Ideally, drinking water should have a pH close to neutral.
Corrosive water is defined as water having a low pH (acidic), low alkalinity (ability to neutralize acids), high carbon dioxide content, high oxygen content, and low hardness (soft water). The presence of minerals/salts and fine particles, and high temperature also add to corrosiveness. Corrosive water can cause leaching of lead, and other metals from pipes and faucets.
What are some signs of having corrosive water or Lead contamination?
Signs that you may have corrosive water are cold tap water having a bitter taste, blue-green stains in bathtubs, sinks and around faucets, and leaky pipes. However, lead contaminated water has no signs! Because It looks, tastes, and smells just like uncontaminated water, the only way to know if you have lead in your water is to have it tested.
If you live in the Midwest or Northeastern areas of the United States, where some lead service pipe-lines are still used, it is possible that lead may be present in your tap water. However, proper water treatment for the control of corrosive water should prevent lead from leaching into the water as it moves from the plant to your home. This is also the reason why you have hard water. Water is made hard to help in the prevention of pipe corrosion.
Where does Lead in drinking water come from?
Lead in drinking water comes from it being leached from pipes, solder, and other plumbing material that contain lead (this is where the lead in Flint Michigan came from; not the river). As the material corrodes lead is freed and is transported in the water to your tap. It is very unlikely that source water (river, lake, reservoir, well) is the origin of lead contamination.
The problem with detecting Lead in drinking water.
Contrary to popular belief, water utilities have little control over most sources of lead in drinking water. Again, this is because after the water is treated and released, lead is picked up in the pipe-line or close-to-home, in home plumbing. However, water companies are required by the Lead and Copper Rule of 1991, set in place by the EPA, to monitor lead levels by sampling tap water from customers homes. Sample collection is required every 6 month, unless qualified for reduced monitoring, from 10% of homes. Regardless, no safe blood level threshold has been identified for children, and when lead is detected it is only required that citizen be notified and educated on lead toxicity and how to reduce exposure.
How can you reduce your risk of Lead Poisoning?
Lead exposure can be reduced by letting your tap water run for a minute or more before using it for drinking or cooking. Also, using only cold water for preparation of formula and food; high temperatures can liberate more metals from pipes. Ingesting lead on an empty stomach can increase the amount of lead absorbed into the body, as well as, being deficient in calcium, iron, and zinc. Children and pregnant woman are most at risk do to higher demands for calcium related to growth and development.
What else can be leached from pipes due to corrosive water?
The brown or yellow color and foul smelling odor residents reported the water to have, are not do to the presence of lead. This is most likely the result of other heavy metals, such as Copper(Cu) and Iron (Fe) which can be released from pipes as a result of corrosion. Iron and copper compounds can have a blue, red (think rust), or green color. Copper complexes with zinc or tin have a brass (brownish-red) color. Where there is corrosive water and corroded pipes there may also be bacterial contamination and this too can lead to foul odor.
Copper and iron are both essential metals necessary for the proper function of the body. Copper has antimicrobial and wound healing properties, and Iron is used therapeutically in the treatment of anemia. However, both copper and iron can be toxic when ingested in large amounts; whether acutely or chronically. Acute toxicity of both metals causes nausea, vomiting, and irritation of parts or all of the gastrointestinal tract. Chronic exposure of both metals causes liver damage; the Liver is the target organ of copper toxicity and its necrosis leads to red blood cell destruction (anemia). Additionally, chronic Iron toxicity can result in cardiovascular disease, hormonal imbalance, and diabetes mellitus. Coincidentally, the presence of copper and/or iron in the Flint tap water, acted as a colorimetric warning sign to residents that something was wrong; as lead contamination has no visible sign or scent.
Water companies test water before, during, and after treatment, but once it is released it can pick up contamination before it arrives at your tap. Water from the Flint River itself does not contain lead, but has naturally high levels of chloride, a salt ion that increase corrosiveness greatly. Lead water contamination however, is a known source of neurologic toxicity. It is especially dangerous to the developing brain, and chronic exposure can result in learning disabilities and memory deficits. Ironically, lead and copper are used in plumbing due to their high resistance to corrosion. However, everything has its limit, and as a result the corrosiveness of the water has to be accounted for. At the right pH these metals can safely be used, but as with all things the dose makes the poison. In this case the power of hydrogen made the poison.