Maintenance of old homes can be an extremely hazardous activity if improperly done. For example, lead poisoning can arise from exposure to lead-based paint chips as well as dust produced during prep work for repainting. A variety of metals exist in old paint besides lead, including cadmium, manganese, nickel, copper, cobalt, chromium, and vanadium.
There are usually two methods followed for removing old paint – power sanding [paint is sanded away or removed with heat] and scraping [A chemical paint or varnish remover is used to soften the painted surface. Then, the old paint can be scraped off or washed away with water].

By pulverizing old paint, power sanding can release many paintbound metals that accumulate in the environment because they don’t decompose. In addition to lead, power sanding can release enough cadmium, manganese, and nickel to not only place painters at risk of overexposure but also contribute to exposure during a critical window of childhood that may contribute to chronic health problems later on in life. Scraping paint is a relatively safe method for preparation and that it doesn’t contribute to lead dust accumulation in either the interior or exterior of a house. To be effective, though, scraping must be accompanied by diligent cleaning practices.
Paint should be tested for lead before any painting project is begun, and power sanding should be prohibited.