by Marie S. Neri, SunStar Daily

MANILA -- Pesticide in cassava sweets poisoned more than 100 grade school students in Bohol, the Department of Health (DOH) said Monday.

Health Secretary Manuel Dayrit said the results of laboratory examinations conducted by the University of the Philippines-Poison Management and Control Center (UP-PMCC) showed that "carbamate" poisoning killed 28 children and caused vomiting and diarrhea spells in 77 others recuperating in three hospitals in Bohol.

Carbamates and organophosphates are two classes of insecticides containing chemicals designed to kill insects by inhibiting a key enzyme in their nervous system called cholinesterase, which is also a component of the human nervous system.

"Based on the examination, the cause of death of children was diarrhea and dehydration secondary to pesticide and also possibly secondary to an infectious agent," Dayrit said.

While the DOH has already pinpointed pesticide poisoning as the cause, Dayrit said there are other factors that might have aggravated the situation and resulted in a high number of children getting killed or ill.

"Chronic exposure to pesticides," which is present in the environment in Mabini, Bohol, was noted, Dayrit said.

"The overall picture here is you have a highly contaminated environment and pesticides and bacteria in the same place where the food was prepared, halo-halo yung (there was a mix of) food and pesticides, and these may have infectious agents," he added.

He said of the 49 grade school pupils tested, 82 percent of those who ate a local snack food called "maruya" suffered diarrhea while 62 percent of those who did not eat the same food also got diarrhea.

The same statistical analysis also showed that 94 percent of those who ate "maruya" suffered vomiting spells while 66 percent who did not eat "maruya" also vomited.

Seventy-nine percent of the victims suffered a headache as against 66 percent who did not eat "maruya" but still had a headache. About 83 percent suffered abdominal pain compared to 57 percent who did not take "maruya" and still suffered stomach pain.

Dayrit said the health experts noted that abdominal pain was "statistically significant" in the tests because 83 percent of the 49 students recuperating in hospitals suffered stomach pain.

He added the examination also showed the children tested had low levels of cholinesterase, one of many important enzymes needed for the proper functioning of the nervous system of humans.

Among the signs and symptoms of cholinesterase inhibition are: tiredness, weakness, dizziness, nausea and blurred vision in mild cases; headache, sweating, tearing, drooling, vomiting and twitching in moderate cases; and abdominal cramps, diarrhea, muscular tremors, staggering gait, slow heartbeat, abnormally low blood pressure and breathing difficulty and possibly death in severe cases.

It was also discovered that the Bohol patients that were given atropine, an antidote to pesticide poisoning, and activated charcoal responded to the treatment and were rehydrated.

"They found some level of depression of cholinesterase and because many of the patients responded to atropine, this is why they were concluding that it is most likely pesticide," Dayrit added.

Food and blood samples taken last week from the victims in Bohol showed cyanide poisoning was not the cause since the amount or level of cyanide in the blood samples was not significant.

"Based on the conclusion, there is no evidence of cyanide poisoning among the children who were brought to the hospital," Dayrit said.

Dayrit said blood samples collected from the victims showed the range of the cyanide content was from 0 to 0.2 milligrams per liter, which is not enough to conclude there was cyanide poisoning since you need at least 0.5 milligrams per liter before you could attribute it to cyanide.

"If you will compare the cyanide in the cassava it will not give you a very rapid onset or that fast to produce symptoms," said Dr. Irma Makalinao, one of the UP toxicologists sent to Bohol.

She also said the body has enzymes that can equalize the effect of cyanide.

Asked if the DOH will recommend the filing of charges against the vendors of the contaminated snack food, Dayrit said it is not in their jurisdiction to do so.

"It's the medico-legal experts who would have to take over and determine the culpability of the vendor," Dayrit said.

Dayrit said they are coordinating with the Philippine Fertilizer and Pesticide Authority as well as the Department of Education to inform the public on the dangers of pesticide use.

It was learned that carbamate was present not only in agricultural pesticides but also in insecticides commonly used in households.