High 1950s and 1960's dietary intake of dairy and meat fats from livestock dipped in organochlorines or grazed on treated pasture [or sometimes both] combined with high New Zealand per capita use rates of both DDT and 2,4,5-T amongst if not the highest in the world created significant opportunity for 1950s, 60s and early 70s food-chain (dietary) exposures to a mixture of lipid (fat) bound bio-accumulative organochlorines insecticide and herbicide contaminant residues.
Ironically although N.Z banned visits of American nuclear ships in the 1980's, then promoted our clean green status, it was the earlier American action of testing*A01 and impounding contaminated N.Z. beef*A02 in 1961, which had ended dipping*A03 in Aldrin and Dieldrin, ended BHC use and led to modification of N.Z. DDT use. In 1963-1964 Dieldrin and Aldrin were disposed*A63 of by spraying onto N.Z. [Govt.] lands and survey farms. Ongoing residue residue monitoring*A04 of N.Z meat was introduced in 1961, as well as a series of N.Z studies [three on samples from corpses] to confirm that N.Z. human residue levels were reducing.
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| RIPPINGHAM GRANGE N.Z BEEF CARGO IMPOUNDED IN USA 1961 DUE TO CHEMICAL RESIDUES |
On November 4, 1969 the US Embassy*A05a notified N.Z officials of new USA restrictions on domestic 2,4,5-T use after 2,4,5-T / TCDD animal studies detected birth defects. Both 1961 and 1969 American actions led to responses eventually reducing N.Z food-chain residue exposure. Public attention and controversy over 2,4,5-T use and production focused primarily on the period of 'cleaned up' 2,4,5-T with reduced TCDD levels from 1973-87, in particular official reports on rural birth defect clusters, IWD workers and N.Z 2,4,5-T sprayers in response to ongoing public controversy.
Official American responses included reducing the allowable TCDD levels and also significantly reducing the domestic use*A06a of 2,4,5-T and ending U.S military defoliant use in Vietnam. Contrast New Zealand where the Government introduced a subsidy in mid 1969 promoting the increased production and use*A07 of IWD 2,4,5-T and only reduced the allowable level of TCDD in 2,4,5-T, several years later*A08 1972.
Although N.Z consumption of animal fats and use of organochlorines was high there were 91 breast milk studies internationally before the N.Z 1987/88 breast milk study. Officials knew residues in the population had reducing from the mid 1960s on and IWD 2,4,5-T TCDD levels had reduced 20 fold 1971 to 1973.
Long term investigations into the effects of continued ingestion of insecticides and weed-killers and residues were first recommended by the N.Z. Royal Society in 1957.*A09 These suggested long term health studies of the N.Z population were never implemented. In 1986, nationwide studies on residues of 2,4,5-T and TCDD were again recommended. In response small studies of residues were conducted on sheep meat and human breast milk. However, nationwide studies were not conducted until the mid-late 1990s.
The long delayed New Zealand health assessments used only the late 1990s dioxin and PCB population residue levels, noting that the 1990s dioxin levels may cause 1 to 7 extra cancers per 1000 and were close to levels which causing reproductive effects in animals. The 1990's residue levels presented a better lower 'clean green' exposure scenario than peak 1960's early 1970s residues in the population from the mixture of organochlorines heavily used in New Zealand*A10 from 1950 to 1970.
Press releases*A12 noted dioxin levels were reducing*A13 and exposure was to be further reduced by limiting the backyard rubbish burning. This media strategy was very effective, in directing N.Z media away from peak 1950s and 1960's*A11 exposures. Exposures that were followed by a period when Health Department statistics centre records show nationwide birth defects increased from 12.8 per 1000 in 1960 to 20.8 per 1000 in 1970 and from 1960 the incidence of cancer in New Zealand has doubled, as reported in Health Indicators [8.11.2002] in the Parliamentary library. Both National and Labour Government media strategies were effective in re-framing and downplaying both organochlorine exposure and health issues as to reassure the public.
Researchers were surprised in 2002 when a study published in the 'Lancet' on around 1000 children born between 1972 and early 1973 in Dunedin, N.Z, found that children breastfed for four weeks or longer were around twice as likely to have allergic disease or asthma in later childhood than children who were not breastfed. Breastfeeding effects were not affected by parental history of hay-fever or asthma. Health Indicators 8.11.2002 also reports N.Z incidence of asthma is among the world's highest.
"By 2007 sperm counts in N.Z men have halved over the last 20 years. This is the most dramatic fall in Western countries. These findings are based on quality data from men volunteering as sperm donors. In Australia and the USA no decline has been seen during the same time period." TVNZ 11.11.2008.
Unfortunately recent studies investigating intergenerational epigenetic mechanisms in chemically exposed laboratory animals suggest that mechanisms passing the impacts and effects of chemical exposures, across multiple generations, may in fact exist.*A14
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