Title: Human health impacts of exposure to herbicides and pesticides: a review

Summary: The objectives of this paper are to provide a summary scientific review of peer‐reviewed literature on the human health impacts of exposure to pesticides, especially those that may be impacting Australia’s Great Barrier Reef; and to briefly review key international concerns and emerging approaches to pesticide issues. Evidence is provided of the increased risk of some adverse health effects from exposure to pesticides. There is evidence that a number of the pesticides found in the Great Barrier Reef waters and in waterways discharging into the area may cause cancer (e.g. atrazine, 2,4‐D,diuron, simazine), neurological conditions (chlorpyrifos), birth defects (atrazine, 2,4‐D, diuron, endosulfan, MCPA), reduced foetal growth (atrazine, chlorpyrifos, 2,4‐D,metolachlor), and metabolic problems leading to obesity and diabetes (chlorpyrifos). Foetal and early childhood exposures to pesticides are a key concern, with considerable evidence of links between such exposures to a wide variety of pesticides and a range of childhood cancers, especially brain cancer and leukaemia. Prenatal exposure, particularly to organophosphate insecticides, is strongly linked with a range of developmental, cognitive and behaviour deficits, that can result in lasting adverse effects on the brain and leading towhat has been described as a “silent pandemic” of developmental neurotoxicity. Prenatal exposure is also strongly linked with a range of birth defects. More …

Key systemic effects underlying many of these conditions involve the endocrine and immune systems. Exposures to endocrine disrupting chemicals (EDCs) during these early life stages can have permanent and irreversible effects, with s evere health consequences throughout childhood and into adulthood, and even for subsequent generations, the effects continuing long after the exposure to the endocrine disrupting chemical has ceased. ‘Inert’ ingredients are added to pesticide formulations for a number of reasons includinghelping the product stick to the surface of leaves and soil, spread over surfaces, or dissolvein water. They can be more toxic than the active pesticidal ingredient to humans, non target plants, animals and microorganisms. For example the ‘inert’ ingredients in glyphosate increase its aquatic toxicity. Generally there is no requirement to identify the inert ingredients on pesticide labels or publically available registration information, and pesticide proprietors claim the identity of ‘inerts’ as confidential business information. This makes it impossible for the general public or researchers to know what is in the formulations being used.

Areas of pesticide toxicology and policy of key international concern include endocrine disrupting chemicals, low dose exposures, chemical mixtures, hazard versus risk assessment in pesticide regulation, precaution, substitution, and causing minimum harm to humans and the environment through pest management techniques.Increasingly hazard assessment is coming to replace risk assessment as it is realised that the current regulatory process of assessing the risk of a single pesticide at a time fails to account for the reality of human exposure to ongoing low doses of mixtures of pesticides. Currently no country has an adequate regulatory process for assessing these effects, or those of endocrine disrupting pesticides. Nor do they adequately implement the precautionary principle, or the substitution of ... nonchemical methods. None at all work on the basis of the principle of minimum harm, asking the first question: how do we control pest, weeds and diseases in the manner that is least harmful to people and the environment.

[ Source: Watts, M. Human health impacts of exposure to pesitcides. Meriel Watts Research and Consulting, Auckland, New Zealand. on-line, accessed 21/03/2013. 10.44am. Photo credit: CSIRO]

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Article: WeedsNews4346 (permalink)
Categories: :WeedsNews:research alert, :WeedsNews:pollination, :WeedsNews:herbicides, :WeedsNews:health
Date: 21 March 2013; 10:51:43 am Australian Eastern Daylight Time

Author Name: David Low
Author ID: adminDavid