500 tonnes of toxic pesticide DDT removed from Chattogram after 37 years

What is thought to be the world's largest remaining stockpile of banned pesticide dichlorodiphenyltrichloroethane (DDT), left in Chattogram city for 37 years, has finally been removed.

DDT is toxic to humans and other organisms. It harms fertility and reproductive processes, disrupts hormonal systems, and is a probable carcinogen. As a persistent organic pollutant (POP), it accumulates in the bodies of humans and animals, as well as the wider environment.

The UN Food and Agriculture Organization of the United Nations (FAO) supported the government to dispose of the DDT safely and clean up the storage site in a complex international operation.

The final batch of repackaged DDT will be loaded onto a ship later this week and then the entire consignment will set sail for France where the waste will be incinerated at a specialist facility, the FAO said Wednesday.

France is one of only a handful of countries that can dispose of DDT safely and also allows the import of hazardous waste from other countries.

Bangladesh imported 500 tonnes (500,000kg) of the pesticide in 1985 to control malaria-carrying mosquitos but the consignment was deemed technically non-compliant. Upon arrival, it was put into a government compound, the medical sub-depot of the Directorate General of Health Services in Agrabad.

Over the years, many of the boxes and bags disintegrated leaving exposed piles of the white DDT powder. In 1991 Bangladesh imposed a DDT ban but the huge consignment remained.

FAO consultant Mark Davis, an expert on obsolete pesticides, said: "This is the largest amount of the pesticide removed from a single location that I'm aware of. It's also highly unusual in that it was stored in the middle of a city and because it was there for so long."

Since DDT does not break down, the consignment has the same concentration of active ingredients today as it did when it was manufactured.

Due to the urban location, special precautions were taken to ensure that the DDT removal operation did not create dust. The buildings were sealed and operated under negative air pressure to ensure that everything stayed inside.

Mark, who oversaw the operation, stressed the high safety standards of the removal and clean-up. "This is a large quantity of a dangerous substance stored in an urban environment. Our operation applied all necessary measures to ensure that nobody was exposed and that none of the chemicals spread into the environment. The safety standards applied were the same as they would have been in Europe."

Under the supervision of FAO experts and government officials, a specialist company based in Greece took four months to complete the repacking of the DDT at the site. In the hot and humid conditions, trained workers wearing full hazardous material protective suits worked alongside specialist machinery.

In some situations, they had to hand-shovel the DDT because it was unsafe to use machinery inside the building. The DDT was loaded into high-specification, UN-approved chemical containers that were then loaded onto 24 shipping containers.

Removal of DDT is highly technical and bound by international laws, rules and regulations. Fourteen countries had to give their permission for the ship carrying the waste to transit through their territorial waters, namely Sri Lanka, Malaysia, Turkey, Egypt, Malta, Italy, Spain, Portugal, Morocco, the UK, the Netherlands, Belgium, Germany, and France.

Robert D Simpson, FAO representative in Bangladesh, said: "DDT has no place for use in controlling malaria or in modern agriculture. The removal of the DDT after such a long time is a very welcome development for Bangladesh, in particular for the people of Chattogram."

"Appreciation is due to the ministries, local authorities of Chattogram, the company that removed the DDT, and in particular the frontline workers who packaged the DDT during the last months."

Saso Martinov, who led the FAO project which removed the DDT, said: "This was a complex and highly technical operation that took considerable expertise and planning and which was the first of its kind in Bangladesh."

"This is a major achievement but there is still a long way to go in reducing the use of other pesticides in Bangladesh. We want to strengthen governance and enforcement of pesticide use, improve monitoring and reporting of pesticide residues in food, and raise awareness about pesticide contamination in the environment."

While clean of visible traces of DDT, it is impossible to fully decontaminate the buildings and land that are impregnated with DDT after nearly 40 years of exposure. The cleared site will be handed back to the Directorate General of Health Services next year.

Pesticides such as DDT were once hailed as the saviours of agriculture. Accumulated knowledge is showing that pesticides may be causing more harm than good.

The Convention on Biodiversity is calling for a two-thirds reduction in pesticide use globally by 2030, to save biodiversity that is essential for agriculture and our wellbeing. The World Health Organization advocates for the removal of highly hazardous pesticides that cause harm to women and children in particular and to all people who are exposed to them.

The United Nations Environment Programme encourages countries to reduce the use of harmful chemicals and to count the full cost of using these chemicals which includes damage to health, the environment, and trade opportunities.

POPs like DDT were mostly used in tropical and hotter countries where they tended to evaporate and move through the atmosphere to condense and concentrate in colder regions like Canada and northern Russia. So, this is not just a local problem for Chattogram or Bangladesh but rather a global problem.

This is the reason that the Stockholm Convention on POP was negotiated through the UN in 2001. Bangladesh is a member of the Stockholm Convention and has been granted support to solve this problem from the Global Environment Facility which finances that Convention.