Blood tests confirm high levels of dioxin

Blood tests have confirmed that people who lived near a New Plymouth chemical plant have high levels of potentially cancer causing dioxin in their bodies.

The levels of dioxin in the 52 people ranged from no higher than the average in the New Zealand population, to 15 times higher than the average.

The tests were done by the Institute of Environmental Science and Research for the Health Ministry, following community concerns about the former Ivon Watkins-Dow plant in Paritutu.

The plant, now Dow AgroSciences, produced the weed killer 2,4,5,T from 1962 to 1987.

Today's results are from 28 people who have lived near the plant. Results for the 24 people in round one of the testing were published last September.

After the first results were published, the dioxin levels were said to be similar to some of those reported in Vietnam after spraying with Agent Orange 20 to 28 years previously.

People in round one of the study had an average level of TCDD, a dioxin, of 10.4 pico-grams (pg/g) per gram of blood lipids (fat). In round two the average was 3.2 pg/g.
The average for both groups was 6.5 pg/g compared with the average New Zealand national average of 1.7.

ESR says this is a statistically significant elevation.

"TCDD exposure to residents is likely to have been the result of gradual accumulation over a long period of time, as duration of residence was the key factor in determining the likelihood of measuring an increase in serum [blood] TCDD."

Study participants with 15 or more years residence between 1962 and 1987 had average TCDD levels of 14.6 pg/g. The national average for the same age and gender mix is 2.4 pg/g.

Those with less than 15 years exposure were, at 3.2pg/g, over twice the expected level of 1.5 for an age and gender matched group from national data.

The Ministry said last year that the levels of dioxin found in the study could cause up to three extra deaths from cancer in every one hundred people.

But today's ESR report stats that there are still many unknowns, including the potential health effects on people significantly exposed to the pollution.

The ministry also said last year that people who had lived in areas other than Paritutu, or in the suburb after 1987, had not been exposed to dioxins in the way those in the study had been.