Sakchai Kanjanawatana of the National Health Security Office says 5,000 people have sought treatment for over-exposure to these three toxic farm chemicals. (Screen cap via NewsNBT Thailand)

The National Health Security Office (NHSO) is throwing its weight behind growing calls for a total ban on three major farm chemicals, saying around 5,000 people have sought treatment from exposure to toxic substances per year with estimated annual health costs of 22 million baht.

NHSO secretary-general Sakchai Kanjanawatana said health hazards from the use of chemical substances in agriculture are evident based on the NHSO's findings over the past three years. These figures involve only those with direct contact to toxic chemicals, he said.

The NHSO runs the government's universal healthcare programme.

The death toll from toxic chemical exposure in agriculture between 2016-2018 stood at 1,715, or almost 600 a year on average, he said.

Between October 2017 to July 2018, a total of 4,001 patients were treated for direct exposure to dangerous farm chemicals under the universal healthcare scheme supervised by the NHSO, with medical costs reaching 17.3 million baht.

Of the 520 people who died from exposure to farm chemicals, 56 were exposed to organophosphate and carbamate insecticides, 442 were harmed by herbicides and fungicides and the rest from other toxic farm chemicals.

Of 13 health zones across the country, the largest number of patients was in Health Zone 1 (644), followed by Health Zone 9 (454), Health Zone 5 (433), Health Zone 2 (426) and Health Zone 3 (422). These zones cover several farm-based provinces in the North, some Central and northeastern provinces.

According to the NHSO findings, in 2016, a total of 4,924 people sought medical assistance following exposure to dangerous farm chemicals and 613 of them died. In 2017, 4,983 people sought treatment and 582 of them died.

"This information serves as clear evidence of the dangers of chemical substances. NHSO is supporting the public health minister in pushing for a ban on the three chemicals in agriculture," he said.

Dr Sakchai said the danger could be more extensive because these findings do not include long-term threats of farm chemicals to those who are indirectly exposed, and their impact on the environment.

The NHSO's stance is expected to heap pressure on the government after its Hazardous Substance Committee (HSC) revised its decision to ban those substances despite calls from consumer groups for a total and immediate ban.

The chemicals -- paraquat, chlorpyrifos and glyphosate -- are now only partially restricted and can still be used in six kinds of crops, including corn, cassava, sugarcane, rubber, oil palm and fruits.

Consumer advocates say that these chemicals have been banned in other countries for several decades due to serious threats to public health.

However, these pesticides are commonly used because they are inexpensive and produce quick results.

Meanwhile, Deputy Agriculture and Agriculture Cooperatives Minister Wiwat Salyakamthorn on Monday brushed off reports that he would be axed from the cabinet after he pledged to end the use of the three pesticides.

He said the rumour was an attempt to create a conflict between him and Prime Minister Prayut Chan-o-cha and that the prime minister already denied any plan to remove him from the post.

Former Pheu Thai deputy secretary-general Chaowalit Wichayasut joined the chorus Monday against the use of paraquat, chlorpyrifos and glyphosate in farming.

He said these chemicals may pose even more dangers than previously thought because produce, soil and water resources could be contaminated by the pesticides' residue.