"I closed down my factory after the restriction on dismantling batteries came into effect. When the factory was in operation we used to recover 1,000 tonnes of lead from used batteries a year," said Haji Lokman Hossain Khan who owns Madina Metal and Chemical Industry at Kamrangirchar.

According to a study by Waste Concern, an NGO working on recycling and waste management, used lead acid battery (ULAB) recycling is a big recycling sector in the country where around 6,000 people were involved.

In 2006 around 6,26,376 lead acid batteries were dismantled in the country recovering 7,428 tonnes of lead. Apart from lead, all parts of the batteries are recycled for making various products.

Big factories and the backyard smelters on the city outskirts like Kamrangirchar and Kholamora used to recover around 3,000 tonnes of lead a year. The used batteries are collected mainly from scrap shops.

The battery dismantling units were closed down due to a law forbidding unsafe recycling that pollutes environment and affects workers' health.

Lokman Hossain Khan has been in car battery dismantling business since 1980. His Madina Metal was the biggest battery-dismantling factory in the city.

Every part of a scrap battery has a recycle value -- the plastic casing, plate separators and sulphuric acid. Big manufacturers buy the lead for making batteries while the other parts are traded in informal sector.

According to Lokman, around 800 tonnes of lead is imported each month to meet domestic demand. "One tonne of imported lead costs $24,000. By recovering lead locally, we can save more than $20 million every year."

According to the Waste Concern study, locally recovered lead could meet 60 percent of the total lead requirement of the country.

Lokman and other battery dismantling factory owners are now waiting for government approval to resume their business in an environmentally safe method. "We will start our work again after six months after getting proper licence from government. We will import a machine from India to recycle batteries that will not pollute environment. By using that machine we are expecting to recover 65 percent lead," he said.

Iftekhar Enayetullah, director, Waste Concern, put emphasis on passing laws as a first step to stop unsafe recycling of lead acid batteries and introduce a safe method of lead recovery.

Lead poisoning causes serious environmental and health hazards, especially to children and the battery-dismantling workers. It affects human brain and may even lead to death, Enayetullah said.

During the process of dismantling lead acid batteries, a large volume of acid, lead smoke, lead dust, fuel smoke (from coal burning) and burnt coal is released, causing air, water and soil pollution, he added.

According to an estimate of World Health Organisation, 120 million people are exposed to lead and 99 percent of the severely affected are from developing countries. Batteries account for more than 75 percent cases.

"Big factories like Madina stopped unsafe dismantling after the restriction was imposed. We first need laws to save people from unsafe recycling and then start doing it safely using modern technology," said Enayetullah.

"The aim of our study on lead acid battery was to solicit the government to pass a law so that people start recycling safely. In future we have a plan to do a study on dry cell battery to stop its unsafe recycling," he said.

At present there is no study on the recycling of dry cell batteries.