When lifesavers take life
In 2004, Health Care Without Harm — an international coalition of 437 organisations — conducted a research on 48 medical products used in European hospitals. About 39 were found to contain di (2-ethylhexyl) phthalate (DEHP) — a toxin found in the products made up of polyvinyl chloride (PVC). It is commonly used as an additive to soften PVC used to manufacture medical products like blood bags, urine bags and tubes. Since DEHP is not chemically bound to PVC, it leaches from the PVC products, depending on various factors, including storage and usage temperatures. Experiments conducted on animals indicate that exposure to DEHP leads to abnormal sexual development as well as skeletal, cardiovascular, eye and neural tube defects. Besides, the toxic effects of DEHP include damage to the heart, liver, kidneys, lungs and testes of laboratory animals. The US National Toxicology Program and the International Agency for Research on Cancer have classified DEHP as a possible human carcinogen.

Its hazards were recognised as early as 1986 when the Consumer Product Safety Commission asked the toy industry to remove it from children's teethers owing to its toxicity and ability to leach through saliva into children's bodies.

While the EU has banned the use of DEHP in cosmetics, personal care products and certain toys, its use in medical products is still rampant. Viable alternatives to vinyl medical products are now available. PVC-free blood platelet containers have hit the market and active research is going on to develop a blood bag substitute.

Trap them!
The Municipal Corporation of Delhi (MCD) has come up with an oviposition trap to deal with the mosquito menace in the city. The trap is a wide-mouthed, pint-sized jar that is partially filled with water. It is usually placed in an area where mosquitoes are likely to spawn. It contains chemicals called pheromones, the ‘smell’ of which attracts the female mosquitoes to lay eggs inside it. These eggs are then destroyed. By analysing the weekly breeding data of mosquitoes, it is also possible to identify the most vulnerable areas in the city, which, in turn, can lead to effective surveillance. This system of surveillance is currently being followed in the slums. This trap has been quite successful in checking the mosquito nuisance in Singapore — a hot spot of malaria. It has helped reduce the annual breeding intensity of Aedes aegypti — the dengue vector — below two per cent since 1979.

Back home, officials hope this method will help save many lives. "The current measures to check the problems of mosquitoes are not foolproof," asserts M A Ansari, senior deputy director of the Malaria Research Centre, New Delhi. "The traps can help overcome the drawbacks of the present system. Moreover, they are cheap and eco-friendly," claims K N Tewari, municipal health officer at MCD. Effectiveness of these traps remains to be seen. Interestingly, after the introduction of these traps, the total number of malaria cases reported in the city till September 2004 was significantly higher than the corresponding figures for the last two years. This is because the positive impacts of this method would be evident this year onwards.

Banning is the only way out
A review of worldwide research on human reproductive disorders related to organochlorines (OCs) points to an urgent need to ban these harmful chemicals. OCs are compounds that can alter hormonal functions, thereby adversely affecting reproductive organs and the health of newborns. Some of the widely used OCs are dichloro-diphenyl-trichloroethane (DDT), poly-chlorobiphenyls (PCBs) and dioxins.

The review was undertaken by Gunnar Toft, researcher, Department of Occupational Hazard, and colleagues of Aarhus University Hospital, Denmark, in November 2004. They analysed 408 studies from countries that have banned OCs as well as those that are still using these chemicals. The researchers studied the following effects: male and female infertility, cancer, spontaneous abortions, prenatal mortality, low birth weight, pre-termed delivery, congenital malformations, skewed sex ratio and early puberty. A strong correlation was found between exposure to OCs — especially DDT and PCBs — and all the abovementioned adverse outcomes.

In another study, researchers from the University Hospital, Sweden, studied the effects of the following OCs: PCBs, hexachlorobenzene, chlordanes and dichlorodiphenyldichloroethyelene (DDE). They found that despite Sweden banning OCs in the 1970s, many babies born in 2003 were suffering from testicular cancers, as their mothers had very high concentration of the chemicals in their body fat. Of the 61 children studied, 44 had testicular cancer, and the OC exposure levels of their mothers ranged between 0.2 and 3,339 nanogramme chemicals per gramme of body fat.

In developing countries that use OCs indiscriminately for manufacturing paints and pesticides, the exposure is via contaminated foodstuff — vegetables, fruits and milk

In developing countries that use OCs indiscriminately for various purposes, such as manufacturing paints and pesticides, the exposure is mainly via contaminated foodstuff — vegetables, fruits and milk. A study by researchers from the US-based Harvard School of Public Health shows that the chances of spontaneous abortions in China rose with increasing concentrations of DDE and DDT in the mothers’ lipid.

The review indicates that a world-wide ban on all OCs is the only way out. "If developing countries continue using OCs, the impacts would be more pronounced and fatal in the future. A world-wide ban means a less toxic legacy," concludes Toft.