Deadly lead
 
In adults, lead at elevated levels is linked to kidney and cardiac disease, high blood pressure, male infertility and problems with the endocrine glands. In children under six, research suggests the equivalent of three grains of sugar daily can cause irreversible damage to the brain and nervous system, intellectual impairment, smaller stature and behavioural difficulties. Published: The Globe and Mail, FOCUS, February 8, 1992 BY DEBORAH JONES, HALIFAX NELL Halse discovered her family was being poisoned by lead when the water main on her street in Saint John, N.B., burst 18 months ago. The city worker who came to repair it suggested she replace the lead pipe from the city water system that runs into the house. "I thought lead was bad, right?" says Ms. Halse. "So I called the water department, and they basically said, patronizingly, 'Well, dear, it's not a big problem. There's lots of lead pipes everywhere and nobody's died of it and there's no need to worry.' " But Ms. Halse, a freelance broadcaster, was sufficiently worried to have the water coming into her home tested for lead. Six weeks later, a health department official called to say a second test was needed. It confirmed the first results: "The lead levels in our water were 28 times the acceptable amount," she says. Blood tests showed that Ms. Halse had higher than normal lead levels; her husband and their five children, then aged seven to 15, also had elevated lead concentrations, though not as high as Ms. Halse's. The family spent $600 to replace the lead pipe leading into their 60- year-old home, but can't afford to overhaul their entire plumbing system to remove other lead sources, such as solder containing lead and brass pipes and fittings. Instead, the Halses run the water for five minutes each morning before drawing drinking or cooking water, and they have stopped using water from the hot tap for cooking. Ms. Halse, 40, has been treated for anemia, which may be related to lead poisoning. The worrisome news about the family's water was just the beginning, however. Assisted by city and provincial health officials, the Halses found high levels of lead in their vacuum cleaner bag, possibly contaminated by a rug that had been exposed to old paint chips. The soil around their house also contained high lead levels: Their home had been stripped of old leaded paint some time ago, and "all those old paint chips probably soaked down into the soil around the house," Ms. Halse speculates. OFFICIALS in Saint John, Canada's oldest city, have recently become authorities on lead contamination, after several local families, including the Halses, were found to have elevated levels of lead in their blood. City water engineer Peter Hanlon, Dr. Richard Scott, a toxicologist at Saint John Regional Hospital and Scott Giffin, a provincial health officer, subsequently conducted a study of 36 homes and residents and discovered several people with high lead levels. More than half the houses had levels above Canadian safety standards and half the residents had greater than acceptable levels in their blood. Lead has been implicated in a range of health problems. In adults, elevated levels have been linked to kidney and cardiac disease, high blood pressure, male infertility and problems with the endocrine glands. Most older children and adults can stand limited exposure to low levels without immediate effects. But for children under six, research shows that even tiny amounts - the equivalent of three grains of sugar daily - can produce irreversible damage to the brain and nervous system, causing intellectual impairment, smaller stature and behavioural difficulties. Studies have shown it also interferes with a child's ability to metabolize Vitamin D, which is necessary for the growth of bones. At high levels lead causes coma, convulsions and death. "There is no biological function for lead, so there are no safe levels of lead," says Dr. Scott. "We feel that people aren't taking lead seriously enough in Canada." People have become complacent, he says, because the metal is no longer used in paint and is now banned in gasoline. "What people are forgetting is we're dealing with the legacy of past uses. The leaded paint and lead (water) services are still there. Now that we understand lower and lower levels of lead cause adverse health effects, I believe we need to re-evaluate the situation in Canada." Lead poisoning is often equated with slum life and peeling paint, but most homes are at risk. According to health officials, here are the most common sources of domestic lead poisoning: Water starts out clean in public utilities, but picks up lead as it runs through plumbing that has lead mains or lead solder. Most paint used in Canada before 1980 contains lead. Even opening and closing a painted door, and particularly any sanding and scraping during renovations, spews lead dust into the air. Soil around old painted buildings is frequently contaminated; children often track it into the house. People who work with lead may bring it home with them on shoes and clothes. Less common sources are old toys, like lead soldiers or playthings painted with lead-based paint; antique ceramics or eating, drinking and cooking implements, including leaded crystal and brass ladles manufactured in countries that haven't banned the use of lead. Children who live or play near contaminated industrial sites risk exposure to lead. Mr. Hanlon's concern about lead poisoning was initially sparked by the discovery of high lead levels in his three-year-old son. "I know there are children out there who have a heck of a lot more exposure that nobody knows about," says Mr. Hanlon. "The big thing is to educate the people who are in a position to do something about it." Jerry Hershovitz, deputy chief of the lead-poisoning prevention branch of the Centers for Disease Control in Atlanta, Ga., calls lead poisoning "the most common and devastating environmental disease of young children in the United States today," affecting between three and four million youngsters - 17 per cent of the population of U.S. youth. "The more we learn about lead's effects on children and fetuses, the lower the blood- lead level at which adverse effects can be documented." Scientists now believe there is no "acceptable" level of lead in the human body. The CDC says adverse effects can be documented at 0.5 micromoles per litre of blood. Canada's maximum acceptable level is currently 1.2 micromoles per litre. (Ms. Halse was found to have a level of 0.72 micromoles.) Dr. Hershovitz says studies show American "children exposed to moderate levels of lead in preschool years were seven times more likely to fail to graduate from high school and six times more likely to have a significant reading disability than children who had lower lead exposures." Last year the CDC began a 20-year program to eliminate lead as an environmental disease through public education, abatement of lead-based paint in housing and from other sources, and national testing of blood- lead levels. "Since virtually all children are at risk for lead poisoning . . . screening of all children younger than six years old is recommended," says Dr. Hershovitz. In Canada, a federal-provincial task force on lead will report its finding to the advisory committee on environmental and occupational health later this month. One of its recommendations is expected to be that Canada lower its acceptable level of lead in blood to 0.5 micromoles to match the CDC guidelines. Task-force member Michael Inskip, a biologist with Health and Welfare Canada, says there are no comprehensive national studies on lead, so the group, which has been together for a year, relied on studies from several provinces, including B.C., Ontario, New Brunswick and Quebec. Dr. Scott, meanwhile, is hoping for change. He points out that if a man-made chemical were found to be as dangerous and pervasive as lead, action to remove it from the environment would immediately be taken. "Lead is simple to test for," he says. "We know how to interpret the numbers and we know some of the long-term effects. We can do something about this one. There are so many other things we can't do anything about." Deborah Jones, a Halifax writer, is a regular contributor to The Globe and Mail. Copyright Deborah Jones 1992 About this website: Text and photos by Deborah Jones except where otherwise noted. Please contact me for reprint rights. All material copyrighted ../About.htmlshapeimage_1_link_0
The household poison that won't go away
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