Glyphosate Exposure through the Inhalation Route: A Systematic Review

Abstract

          The statistics of the quantity of imported pesticides foragriculture of year 1981-2002, found that the type of
herbicide had an import quantity as the highest among all types of chemicals. The maximum quantity of 148,979
tonswas reported in 2017 and imports approximately 7 times of the insecticide. In 2016, glyphosate which is the
herbicide had been highest imported for 61.80 million kilogram compared to other herbicides. Thailand hadthe
highest import of glyphosate-isopropylammonium and paraquat dichloride annually, thatindicated the use of
glyphosate more than other types of pesticide, and subsequently led to high exposure fromagriculture. A systematic
review of literature aimed to investigate the presentstudiesof glyphosateexposure of users.The World Health
Organization has declared that glyphosateis classified as type 2A carcinogen, namely probably carcinogen to
human.The toxicity of glyphosate is the reproductive system, leading to DNA damage and genetic mutation.
The literatures were included by using keywords of glyphosate, human exposure, ambient air,biomarker and risk
from both domestic and international researchpublication. There were finally 52 studies met the criteriafor the
studied exposure of glyphosate through inhalation route of exposure which showed the highest concentration at
42.96 μg/m3 (6,212.65 ppb) and detection in urine 233 ppb through dermal exposure of farmers. Although, in
Thailand,there has not been yet studiedin glyphosate exposure throughthe inhalationroute, but detected in urine
of farmers that using glyphosate at average concentrations of 13.70 ± 13.30 μgL-1.So far, glyphosate exposure
through inhalation has not beenyet studied, presently, there is no occupational health and safety standard setting
for human exposure to glyphosate during field work. It is therefore very important to develop an occupational
health risk assessment with prospective investigation of inhalation exposurefor setting up a guideline for occupational
exposure level regulation.