Introduction

Purpose of this report

This estimate will allow for an assessment of whether future collections are required to collect and dispose of intractable agrichemicals, and in which New Zealand regions resources should be invested.

This report also demonstrates a key component of New Zealand’s implementation of obligations under the United Nations Stockholm Convention on Persistent Organic Pollutants. Agrichemical POPs are defined as Persistent Organic Pollutants (POPs) under the United Nations Stockholm Convention on Persistent Organic Pollutants.

What are POPs?

Persistent organic pollutants (POPs) are chemical substances that persist in the environment and pose a risk of causing adverse effects to human health and the environment.

The chemicals listed as POPs under the Stockholm Convention are:

• nine pesticides (aldrin, chlordane, DDT, dieldrin, endrin, heptachlor, mirex, hexachlorobenzene and toxaphene)
• PCBs (polychlorinated biphenyls)
• dioxins and furans (polychlorinated dibenzo–p–dioxins or PCDDs, and polychlorinated dibenzofurans or PCDFs).

Environmental and health effects of POPs

POPs persist in the environment for decades and may bioconcentrate significantly. These properties together with their semi–volatility have resulted in the presence of POPs all over the world, even in regions where they have never been used. POPs are everywhere. They have been measured on every continent, at sites representing every major climatic zone and geographic region throughout the world. These include remote regions, where no significant local sources exist and the only reasonable explanation for their presence is long–range transport from other parts of the globe. Referred to as the “grasshopper effect”, POPs released in one part of the world can – through a repeated (and often seasonal) process of evaporation and deposit – be transported through the atmosphere to regions far away from the original source.

POPs are found globally in soils, sediments, in the fat of fish and terrestrial animals, as well as in human breast milk. Some of the highest levels have been recorded in the Arctic region.

Humans are mainly exposed to POPs through eating foods of animal origin, such as meat, dairy products and fish. A growing body of scientific evidence associates exposure to POPs with adverse health effects in humans including cancer, neurotoxic, behavioural, reproductive effects and immutoxicity. The mechanism for some of these effects appears to be through disruption of the human endocrine system. Humans may be sensitive to these chemicals during foetal development.

A growing body of evidence links POPs to reproductive failure, deformities and malfunctions in fish and wild life. Studies from the Great Lakes environment revealed that a dozen Great Lakes predators (such as eagles and turtles) suffered significant health impacts. These impacts included: population decline and reproductive dysfunction; eggshell thinning; metabolic changes; deformities and birth defects; cancers; behavioural changes; abnormally functioning thyroids and other hormone system dysfunction; immune suppression; feminisation of males and masculinisation of females. [Adapted from:Persistent Organic Pollutants and Human Health, World Federation of Public Health Association, May 2000.]

New Zealand’s commitment to the United Nations Stockholm Convention

The United Nations Stockholm Convention on Persistent Organic Pollutants aims to protect human health and the environment by banning the production and use of POPs. New Zealand is a party to the Stockholm Convention, along with 150 other countries. All parties commit themselves to a long–term international effort to reduce or eliminate health and environmental risks from chemicals specified in the convention.

The Convention came into force for New Zealand on 23 December 2004. New legislation was introduced to bring New Zealand’s legislation into line with the legal requirements of the Stockholm Convention. The Hazardous Substances and New Organisms (Stockholm Convention) Amendment 2003 requires that POPs (as defined under the Stockholm Convention) are now banned from importation, production and use in New Zealand.

The storage of POPs chemicals must meet the criteria provided in a Gazette notice released by the Environmental Risk Management Authority (ERMA). [New Zealand Gazette, No 174 Hazardous Substances (Storage and Disposal of Persistent Organic Pollutants) Notice 2004.]

The key obligations for New Zealand under the Convention relating to agrichemical pesticides are:

• Article 3: reduce/eliminate the production, importation and exportation and use of POPs (pesticides and industrial chemicals); and
• Article 6: measures to reduce or eliminate releases of POPs from stockpiles and wastes.

What were agrichemical POPs used for in New Zealand?

From the mid–1940s until the 1970s some pesticides containing POPs (including DDT and dieldrin) were used widely in New Zealand. The main areas of use were agriculture, horticulture and timber treatment. Smaller amounts were also used for amenity purposes and in households.

The use of pesticides in New Zealand was not subject to regulatory control until the Agricultural Chemicals Act 1959 established the Agricultural Chemicals Board. The use of persistent organochlorine pesticides was then progressively restricted by a succession of laws. By the mid–1970s the use of agrichemical POPs had effectively ceased in agriculture and horticulture. All Stockholm Convention POPs were formally deregistered by the Pesticides Board in 1989.