ALTADENA, Calif. — A mother in Altadena started her son on chelation therapy to remove lead from his blood. A geochemist will not enter his home without a respirator and a full-body suit. A cinematographer spent thousands to get the lot where his home once stood tested for heavy metals and remediated — work the government cleanup program did not do. Sixteen months after the Eaton Fire, these are the extreme measures Altadena residents are taking to deal with a host of toxic compounds, including arsenic and asbestos, plaguing their families and properties. The contamination is a result of the unprecedented nature of this urban firestorm, in which thousands of houses and cars became the blaze’s fuel, releasing heavy metals into the smoke. Even after charred debris was cleared from lots where homes burned and after the houses that remained standing were remediated, testing has revealed concentrations of lead high enough to sicken children.…