Cambodian migrant workers face adverse health effects brought on by exposure to pesticides and a lack of protective gear when working on farms in Thailand, a new study has found.

The study, conducted by a group of health researchers and published late last month, shows that more than 75 percent of the migrant workers had abnormal levels of cholinesterase in their blood. Low levels of cholinesterase can lead to dizziness, headaches and nausea, and in more extreme cases, vomiting and diarrhea.

Chemical-resistant clothes and hygiene measures such as washing hands before drinking and taking a shower promptly after applying pesticides can mitigate risks from exposure.

But many of the workers did not use appropriate protection, the study found. Of the 891 workers that took part in the study, more than 80 percent “wore clothes that did not provide adequate protection from pesticide exposure”, often because the employers failed to provide appropriate clothing.

The study also showed that the risk doubled when using backpack-sprayers due to the fine vapours they produce, which can be absorbed easily.

Moreover, there are no health-screening guidelines for migrant workers who were in contact with pesticides in Thailand – something that the researchers argue should be changed.

Another reason for the low use of protection, the study suggested, may be a lack of language skills, making it difficult for the Cambodian workers to understand Thai warnings on pesticide containers.

Touch Van, a researcher with the department of agronomy and soil science at the University of New England in Australia, called for more training about health risks. “It’s not just about the language, but about the habit,” he said, noting such chemicals could weaken the immune system, leaving workers susceptible to other diseases.

He argued that workers should receive a general introductory course about Thailand before moving there and “extra training before they start working” that focuses on risks in the agricultural industry.

Keam Makarady, health and environment director for agriculture NGO CEDAC, which provides training to farmers, said pesticides caused “mostly skin, lung and eye diseases”, and also called for more training.

The Labour Ministry’s Heng Sour said Cambodian workers sometimes received introductory information when moving to Thailand, but declined to comment further, saying he had not read the study.