. >> when gavin walters weight gain wasn't keeping up with his twin garrett. his mother fold up. >> to know that something could have been prevented, that wasn't, because people lied and didn't do their jobs makes me sick. >> i want water. >> you want water? >> gavin who already suffers from a compromised immune system system, suffers from contamination of lead. >> he's a 6.5 shouldn't be over a 5. >> lee ann says the problem came from the city provided water running from her faucet. state tests proved hers has the highest levels that the city had ever seen. >> it shows you the max is 15. >> another independent evaluation by virginia tech researchers showed the levels to be that of hazardous waste. >> oh my god i'm poisoning my kids. if you have issues the question would be, would he have had these issues, if he had not had lead poisoning. >> before tests confirmed it lee ann said city and state officials dismissconcerns when she public ly declared something was wrong with the water. >> i wasn't stupid. i decided to get the science. >> lee ann set out to prove

. >> reporter: when gavin walters weight gain wasn't keeping up with his twin, his mother had his blood tested and uncovered a dangerous diagnosis. >> it was shocking to know that this is something that could have been prevented, that wasn't because people lied and didn't do their jobs. it makes me sick. >> reporter: gavin, who already suffers from a compromised immune system had been poisoned by led >> it says the level is abnormally high and the iron level is abnormally low. these are the explaining. >> reporter: the led poisoning came from the city-provided water running from her own flint michigan faucet. hers had some of the highest led levels the city had ever seen >> this is showing that my first blood result is a maximum of 15. >> reporter: another independent evaluation by researchers found led at levels they considered to be has ordinarious waste. >> i was hysterical. i'm poisoning my kids. if he has behavioural issues, the questions are always going to be, would he have had these issues had he not had led poisoning. they told me that i was a lawyer and this wasn't my water--