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In children lead can interfere with the formation of red blood cells, delay physical and mental development, and impair mental abilities. At high levels of exposure, lead can cause anemia, kidney damage, and mental retardation.
Pregnant women should also be especially cautious about lead exposure, as it can cause premature birth, and reduce the birth weight of babies.
In adults lead can increase blood pressure and interfere with hearing,
The greatest contributions to childhood exposure to lead are lead-based paint, urban soil and dust, leaded petrol fumes and drinking water. Petrol sniffing lunies finish up with brain damage caused mostly by the high lead levels from the petrol.
Lead rarely occurs naturally in drinking water. Instead, lead contamination usually occurs at some point in the water delivery system. It is most commonly caused by the corrosion of lead service connections, pipes, or lead solder used to join copper pipes in the home. Homes that are less than 10 years old and have lead solder or homes that are connected to the water main by a lead service line are more likely to have higher levels of lead in the water.
Lead is now banned from use in pipes and solder in public water systems. It is also banned in household plumbing and limited in brass fixtures.
Lead in drinking water is most commonly caused by the corrosion of lead plumbing materials. Some water is naturally more corrosive. Factors which cause water to be corrosive are acidity, high temperature, low total dissolved solids (TDS) content, and high amounts of dissolved oxygen.
Naturally soft water tends to be corrosive because of acidity, low TDS content, and the presence of dissolved oxygen. Since this natually soft water is corrosive, it is more likely to cause the corrosion of lead plumbing materials.
The process of softening water does not increase the corrosiveness of water. A water softener can significantly reduce the lead level.
Several technologies that treat drinking water in the home have
been proven to significantly reduce lead, in addition to reducing
other contaminants as well. These technologies include reverse osmosis,
distillation, ion exchange resins,
water softening, and solid block and
precoat adsorption filters, which are made with carbon or activated
Prepared by Trevor Croll,
Pearse Street, Keperra, Queensland Australia, 4054.
Phone 61 7 3855 1115