May 22nd, 2018
The Irish adult population is subject to low non-occupational exposure of glyphosate, a novel study from NUI Galway has found.
The results of the first Irish study on exposure to glyphosate, an active ingredient in chemical pesticides used to control weeds, are now published in the journal Environmental Research.
Glyphosate is the most commonly used herbicide globally in conventional agriculture and horticulture to combat weeds.
It is the active ingredient in over 750 products including Roundup and is often sprayed as a pre-harvest drying treatment on certain food crops.
Published in the journal, Environmental Research, the findings from NUIG’s School of Physics indicate that dietary exposure through pesticide residues on fruit, vegetables and grains after spraying is the most common exposure routes among the public.
The researchers and collaborators from the Health and Safety Executive (HSE) in Great Britain measured glyphosate in urine samples provided by 50 Irish adults to estimate background levels of exposure among this population.
Of the 50 urine samples analysed, 20 per cent of the participants had detectable trace levels of glyphosate.
The median concentration of the detectable data was 0.85 µg L-1, 1000 times lower than the Acceptable Daily Intake level for glyphosate set by the European Food Safety Authority (EFSA).
Researchers are cautious, however, that the low proportion of detectable glyphosate levels could be due to “lower localised use of pesticides”, the small sample size or the higher analytical detection limit used in the study.
This could “underestimate the true exposure and warrants further investigation”, the study states.
“Given the widespread use of glyphosate, further information on population exposure is required to advance our understanding of the relationship between chronic low dose exposure to glyphosate and human health risk,” the study states.
Research project supervisor Dr Marie Coggins added that as biomonitoring data across Europe on chemicals such as pesticides are “rare” further studies are required to “fully characterise chemical exposures in humans” to support risk assessment and to inform government policy.
The EU risk assessment process of renewing the substance’s license has been mired in controversy.
The International Agency for Research on Cancer (IARC), the specialised cancer agency of the World Health Organisation, classified glyphosate as probably carcinogenic to humans in 2015.
However, the European Chemicals Agency (ECHA) has said that there isn’t enough scientific evidence currently available to prove that glyphosate causes cancer, with the European Food Safety Agency (EFSA) arriving at the same conclusion in November 2015.
Member States voted last November to accept the European Commission’s proposal to renew the license for glyphosate for an additional five years.
The European Commission originally looked for approval for another decade, however, two previous votes at the Commission’s Standing Committee on Plants, Animals, Food and Feed failed to a reach a qualified majority.
In January, the European Parliament agreed to set up a special committee to investigate the authorisation procedure for glyphosate and other pesticides.
Dublin council glyphosate alternatives
Dublin City Council’s Parks Department recently said that it will try alternatives to the use of glyphosate as a weedkiller on streets and in parks in Dublin.
Three alternatives will be trialled this year in selected areas: Mechanical weed control using spades and shovels; a hot foam with no chemicals; and a method known as ‘New way’ spray which uses vinegar.
Council figures show that three and a half tones of Monsanto’s Roundup glyphosate are purchased in 2014 at a cost of more than €50,000.
Green Party Councillor Ciarán Cuffe, who raised a motion seeking the use of alternative methods of weed control, said that trials should “allow us to choose an alternative method of weed control”.
“I am pleased that Dublin City Council’s Parks Department is moving forward to trialing new methods of weed control. Parents don’t want to see Roundup used in proximity to where their children play,” he added.