The dioxin generated during industrial production and garbage incineration is less toxic than dioxin used in the war, but Le Ke Son, director of the project on handling dioxin in heavily-hit areas in Vietnam, said it was now the right time for the country to take action to deal with the problem.

A report on the dioxin situation in Vietnam released in late 2014 showed that many waste treatment plants in Hanoi, HCM City and Hai Duong province had dioxin and dioxin-like toxic substance concentrations in emission and waste water several times to 5,000 times higher than permitted.

Son emphasized that the toxicity in reality could be even be higher than reported.

“I can say for sure that all the incinerators in Vietnam produce dioxin because they all use outdated technologies,” he said.

The concentration of dioxin that waste treatment plants discharge to the environment depends on three factors, including the types of input garbage and incineration capacity, the incinerator temperature, and the emission treatment technology. 

Son said most incinerators in Vietnam have small capacity.  The temperature of the secondary chamber of incinerators needs to be as high as 1,200oC to be able to fully eliminate dioxin. However, the majority of incinerators in Vietnam cannot reach this ideal temperature.

Meanwhile, at waste treatment plants with outdated technologies, exhaust gas is treated by cooling; therefore, there is high risk of dioxin from plants entering the environment.

As for waste water treatment, Son said, most incinerators running now in Vietnam utilize wet-type treatment technology. 

Researchers have found that the waste water from a waste treatment plant in HCM City contained dioxin content 5,000 times higher than the permitted level in accordance with Japanese standards.
 
Meanwhile, Dr. Nguyen Huy Nga, former head of the Environment Department of the Ministry of Health, said that the incineration technology has been banned in many modern countries because it is considered “dirty” technology that harms human health.

In Vietnam, the Ministries of Science & Technology, Natural Resources & the Environment have also strongly recommended that this incineration technology no longer be used.

Nga said there are some 400 medical waste incinerators, most of which have been used since 2000. Over the last 15 years, medical waste has been treated at incinerators at hospitals.

Also according to Nga, most of the incinerators have small capacity, small scale and outdated technology, which generate high concentrations of dioxin.

“Incinerators can kill germs, but they have many disadvantages, including environmental pollution,” Nga said. 

TP