Safety of popular mosquito coils questioned

Tertiani ZB Simanjuntak, The Jakarta Post, Jakarta

A night without mosquitoes in tropical countries would be a dream come true for many. The annoying buzzing sound and itchy bites by the insects, not to mention the possible infectious diseases they carry, make them unwelcome in every home.

Insecticide can be a great deal of help to get rid of the bloodsuckers. In modern households, thanks to technology, electric mosquito repellents, sprays and coils are popularly used indoors.

Mosquito coils have now become the cheapest and most popular form of household insecticide in the country. In 2000 alone, people spent nearly Rp 920 billion (US$102 million) on the products.

The widespread use of mosquito coils, although debatable, can be traced back to the age-old Indonesian way of burning kluwih (breadfruit) or just lighting a fire to produce smoke to drive away the insects, at least for a while.

The use of the substance is aimed at repelling the pests. The substance is not always toxic but by mixing it with pesticide, it may increase its toxic level.

Even though other insecticides also have the potential to harm people's health, the safe use of mosquito coils is now under scrutiny due to the extensive use of a certain chemical substance to boost its efficacy.

Earlier this year, the Ministry of Agriculture approved the use of octachlorodipropyl ether (a toxic chloroether derivative) in pesticides for five years until February 2006.

The ministerial decree, which doesn't clarify in which manufacturing process the use of the substance is allowed, states that the permit may be reviewed and even revoked if sufficient evidence shows that the substance is harmful.

There has not yet been any research on the side effects of the substance, widely known as S2 or S241, on other living creatures, let alone human beings.

Other countries, including the United States, China and Japan, have conducted tests on how S2 affects living creatures. Two of the tests done in China give conflicting results.

The first test conducted in the early 1990s, ensured its safe use. "But the second in 1998 revealed that S2 can mutate the body's cells, thereby causing cancer, airway irritation and even the uncontrollable proliferation of cells," said Eddy Martono, a scientist at Yogyakarta-based Gadjah Mada University.

He was speaking at a one-day seminar sponsored by the pesticide commission on the use of household pesticides here on Sept. 13.

Robert I. Krieger, head of the personal chemical exposure program at the University of California, told the seminar that such a substance is not even registered in the U.S. as there was not sufficient data on the safe use of S2.

"S2 has never been used for commercial purposes in the U.S. because of the uncertainty of its hazardous side effects when exposed to humans," he said, revealing research conducted 40 years ago regarding the use of the substance.

When a mosquito coil containing S2 was burned, he explained the substance may form the carcinogenic compound bischloromethyl ether, otherwise known as BCME, which enters the human body through inhalation or by being absorbed by the skin.

Krieger pointed out that the S2 residual from a burned coil stays longer indoors, especially in a relatively small room such as a bedroom, can last up to 25 days or in some cases up to two months.

The World Health Organization has categorized BCME as a highly toxic compound, which can build up and remain in the fatty tissues for years and may later cause cancer, in particular lung cancer, he said.

"Children are five times more at risk than adults. Recent research in Japan shows that there is a significant amount of S2 in breast milk.

"Although there have yet to be any confirmed cases, uncertainty over the hazards should halt any decision to use S2 as we don't know what little amount is safe to use," he added.

So far, according to Joeli Hartono, secretary of the pesticide commission that gave recommendations for the use of S2, there are at least three brands of mosquito coils using the substance.

He said that factories registered the use of the substance under a list of miscellaneous substances.

Eddy Martono said that there is actually another substance used in pesticides that doesn't cause cause any toxicity.

"Maybe the industry uses S2 due to economic motives, as the substance is relatively easy to obtain," he said.

Many participants later questioned the government's decision to allow its use without providing sufficient information.

"Why should consumers bear the risk of something they are not even aware of?" contended Carolina, a researcher at the Indonesian Institute of Sciences (LIPI).

Tini Hadad, co-founder of the Indonesia Consumers Foundation, urged the government to introduce strict regulations on the advertisements of all mosquito repellents.

"The consumer should be given accurate information on its content, how to use it or the safe dosage of use, because with or without S2, all of the products are toxic and hazardous substances," she said.

Tini also urged consumers to reduce dependence on mosquito repellents and suggested the old-fashioned way instead.

"Just keep the house clean, outside and inside... place mosquitoes screens on doors and windows, nets in bedrooms to prevent the insects from entering," she added.