Final Report on Lead and Arsenic Testing Available
The Nova Scotia Department of Health and the Cape Breton District Health Authority have completed the final report on lead and arsenic testing carried out among Sydney residents in the summer.
The results show that those tested do not have higher exposure to lead and arsenic than those in other communities in Canada, the United States and Europe -- communities both with and without concerns about lead and arsenic in the soil. Results also show exposure levels were similar in neighbourhoods throughout Sydney and were not related to distance from the coke ovens or tar ponds sites.
"The results of the testing are very reassuring," said Dr. Maureen Baikie, the province's associate medical officer of health. "This report is not based on modeling. It is a real, accurate reflection of exposure in the community, and we're not seeing anything unusual."
A total of 372 people volunteered for testing. This represents 44 per cent of children between the ages of one and five, 61 per cent of pregnant women in areas of Ashby, Whitney Pier and the North End, and 30 per cent of all residents in the area north of the coke ovens.
Tests measured blood lead and urine arsenic. Those with blood lead levels above 10 micrograms per decilitre and those with inorganic urinary arsenic levels above 20 micrograms per litre were investigated further.
"The public anxiety around test results in the summer was very high, and this report should help to relieve some of that anxiety," said Dr. Baikie. "It's important to know that we all have some level of lead and arsenic in our bodies. It comes from our food, water and many other sources in our environment."
Dr. Baikie said health effects were not expected or found in those whose blood lead and urine arsenic were at the followup levels used in the testing program.
Blood lead levels averaged 1.9 micrograms per decilitre. Two adults were above the followup level for lead while no children required followup.
There is a well-documented relationship between blood lead levels and health effects. There are also clear guidelines for public health intervention. Dr. Baikie said that blood lead levels in Sydney are low and that, from a public health perspective, the community is not at increased risk from lead in soil.
Results were compared to several other studies, such as the National Health and Nutrition Examination Survey in the United States (1999), which showed average blood lead levels of 2 micrograms per decilitre in children between the ages of one and five.
While there are clear guidelines for interpreting blood lead results, there are no similar guidelines for arsenic in urine. A followup level of 20 micrograms per litre was set based on other community studies to flag potential exposure. Urinary inorganic arsenic levels averaged 4.5 micrograms per litre overall and 3.8 micrograms per litre for children.
Of the 372 people tested, 15 had results above 20 micrograms per litre on the initial test. Only two remained above that level on a second, more precise, test. Those individuals were assessed by a specialist, and investigation into the source of the arsenic exposure continues.
Overall, the testing shows exposure levels in Sydney that fall within the normal range for communities in other parts of Canada and the United States. The Sydney results are also well below reported levels in European populations in areas with no known sources of arsenic in the soil.
Dr. Andrew Lynk, a pediatrician with the Cape Breton District Health Authority, helped design the testing protocol and provided followup for several children.
"We were particularly pleased that lead was not an issue for children because of the known health effects," said Dr. Lynk.
He said that while he did meet with several understandably concerned parents, he was reassured by the fact that all the involved children he examined and tested appeared healthy.
The report on lead and arsenic testing includes results available up to Oct. 31 from public health clinics and family physicians. A copy of the report is available on the Web site at www.gov.ns.ca/health , or at the Public Health Services offices, located on the second floor of the Nova Scotia Power Building, 235 Townsend St., Sydney..