POP part 3: Increasing poison with age, Auckland & Waikato worse, NZ overall still better

Continuing on the series about persistent organic pollutants POP's. First is the figure of blood levels of POP's by region in NZ. There are two points to note. Firstly that the blood level rises over time. This is due to a somewhat constant exposure, but due to the body taking 7 - 10 years to remove a POP, it means that we are exposed to POP's faster than we can remove them. The other disturbing piece of information is that Waikato area and Auckland area are higher than rest of the country. Auckland region is likely to be higher because of air pollution and more contaminates being found in the soil which migrates into the food chain. Waikato is a bit surprising as it is a largely agricultural area. Therefore I would hypothesize that it is due to the sprays that have been used, and continue to be used in the agriculture. In the USA it was found that counter intuitively that kids in rural communities were more likely to get cancer than in the city, again the researches thought this was due to the chemicals used in agriculture.   

However this might not be the case.... the following graph is for DDT metabolites in the blood. DDT has been banded for decades, however it hangs around in the environment for a long time.Waikato and Auckland have low levels, while South Island and the lower part of the North Island have higher levels, even in the lower age groups. I wonder if sheep farming used DDT more than other agricultural uses? Or is it due to other soil residues...

Lastly breaking down the data into ethnicity and sex there is a clear sex bias with males having higher levels than females. The two tall graphs in 50-64 age bracket have very low number of people, 5 and 7 respectively. Therefore these are not particularity indicative of the whole population. So even in the 15-24 group males have higher levels than females. PCB congeners is the technical name for PCB chemicals.

Various PCB's were banned in 1989 and total ban in 1994. Disturbingly PCB's can easily migrate through skin and through latex rubber gloves. Furthermore they are present in a number of situations were I personally could have been contaminated! This includes:

• Capacitors 
• Eelectrical transformers
• Plasticizers in paints and cements
• Stabilizing additives in flexible PVC coatings of electrical wiring and electronic components
• Pesticide extenders
• Cutting oils 
• Flame retardants 
• Lubricating oils 
• Adhesives 
• Wwood floor finishes 
• Water-proofing compounds
• Vacuum pump fluids.

This list is only the ones that I could have been exposed to. Given that I am a "hands on" type of guy, who took his first bit of electronics apart when I was about 6, in 1982 I could have had over a decade of exposure without knowing it! Given that NZ's in general like to "muck in" and historically (and maybe even still) boys like to much in more than girls, hence the sex difference.

Given my exposure might be high..... makes me wonder where I can get my blood tested !

Ending on a positive note..... NZ compared to other countries continue to have low concentration. For instance the graph below compares our PCDD's to international levels. We are definitely in the low end and this was the case for all POP's measured in NZ'ers blood. So I guess I can rest a bit easier cause in general my exposure is lower than other countries.

Reference: Concentrations of selected organochlorines in the serum of the non-occupationally exposed New Zealand population Organochlorines Programme. Ministry for the Environment. May 2001