The lead-contaminated water scandal in Flint, USA, has led to research into the level of chlorine in water. It also appears that the chlorine level was not sufficient to prevent Legionnaires’ disease, a serious bacterial infection of the lung.
We are at the start of 2016 in Flint, a town of 125,000 inhabitants in the state of Michigan, in the United States. A wave of lead poisoning hits adults but also, and above all, children. The rate of Legionnaires’ disease, or Legionellosis, is skyrocketing. It is an acute bacterial infection of the lung, which is potentially very dangerous.
In question: the degradation of the lead pipes, which contaminated the water. But also the change of water supply. The water from Lake Huron was replaced by water from the Flint River, which was polluted and became corrosive.
In a study, published in the Proceedings of the National Academy of Sciences, researchers also link an insufficient level of chlorine in the water which allowed dangerous bacteria to thrive in the water.
Chlorine, needed to kill bacteria
Usually, suppliers add chlorine to the water in order to control bacteria. A team of researchers from the University of Colorado compared the chlorine level and the rate of Legionnaires’ disease at different stations in the city.
Chlorine reacts with organic matter and certain metal ions. If there is too much of it in the water, there is not enough “free” chlorine left to kill bacteria and germs. Consequence: the authorities cannot determine what level of chlorine they must add to the water so that it is not contaminated.
For the researchers, the polluted water of the Flint River as well as the poor condition of the pipes released lead into the water, but also ions that were apparently harmless, but which absorbed the chlorine and suppressed its beneficial effects.
A crisis still not over
Two and a half years after the start of the crisis, a large part of the inhabitants of the town of Flint do not have drinking water.
They are advised to boil the water before using it. Because even if the water supply has again been changed, the pipes near the city, they remain heavily damaged.
Five officials have been charged with manslaughter after their warnings were given too late.
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