Lead Ripples ── Scientist who protected residents from the worst water pollution pollution in American history

Paradeno is already skeptical about these tests.Just like the majority of flint residents, he no longer trusts the human beings.If someone saves the flint, it's probably the people who grew up here like paradinos.

But he could find a reliable person.It is a person who took the initiative in helping the residents and trying to understand what was happening in Frint.He is a scientist at the forefront of the fight against the catastrophe and a hero of everyone.Who can affirm that the government is doing the right thing in this city where a state soldier wearing military uniform carries water to a water office and a medical person is collecting blood in churches and elementary schools?Paradeno says."When Mark Edwards came, I finally knew if the officials were doing what the officials were doing."

Earlier in 2003, a subcontractor called the Kadmos Group had been investigating strange issues, commissioned by the Environmental Protection Agency (EPA).There were many cases where small water leaks were found in water pipes in the entire area of Washington DC residential areas.Kadmos hired a young environmental engineer at a Virginia Institute of Technology called Mark Edwards.

Leakage seems to be limited to copper water supply pipes for home, and no problems were found in poly -chlorized Vinyl pipes and water pipes managed by the city.Edwards thought that there was a problem with tap water in the city.In the United States, drinking water supplied by local governments is protected by the Drinking Water Safety Act, which requires water operators to monitor microorganisms and disinfectants.In 1998, EPA strengthened its standards for disinfectants that generate toxic chemicals.Chlorine is a well -known harmful substance.Chloramine (actually mere chlorine and ammonia compounds), which is often used as a substitute for chlorine, has a small amount of carcinogens, but as a result, metal corrosion is caused by increasing the corrosion of water.In 2000, the Washington Water Sewerage Agency changed disinfectants from chlorine to chloramine.

Edwards, who visited the house to check the damage, was much more scary than water leaks.A strong corrosive tap water melted a solder used to join the water pipe.It contained lead, and corrosion was occurring on the water meter or faucet with lead brass.When Edwards performed water quality tests for tap water in a room on the first floor of an old apartment, the measured value became an error.When the sample was diluted with distilled water and then re -measured, the result of the lead content was 1250 ppb (PARTS PER Billion).The standard value set by the EPA is 15 ppb.

Lead is an inconspicuous but convenient metal. Hard, flexible, relatively easy to be mined. The melting point is low to the extent that processing is possible and does not rust. In the Roman Empire, it was used for piping. The word "plumbing", which means piping system in English, comes from Latin lead (plumbum). Even in 312 BC, when the oldest Roman water supply, Appi Channel, was completed, people were aware that the lead seemed to be toxic. However, as Pittsburg's economist Welner Tesken explained in his book, The Great Lead Water Pipe Disaster, there are problems with lead tubes, but there are many benefits to compensating for it. Among the 19th -century waterwritten scholars (a scholar who studied water circulation on the earth), it was known that cholera bacteria existed in lakes and spring. Nevertheless, they needed a large and hygienic water source to cover the living water in the city. The lead water pipe made it possible.