June 7, 1996. Copyright, 1996, Graphic News. All rights reserved

CALL FOR RESEARCH
INTO FALLING FERTILITY
By Laura Spinney, Science Editor

LONDON, June 7, Graphic News - The scare over 'very small' amounts of phthalate chemicals in formula babymilk has been blown out of proportion, says a British doctor this week.  The current lack of research into environmental pollutants that have adverse effects on humans is far more worrying.
Phthalates, which are derived from oil and natural gas, are known to mimic the effects of oestrogen, the female sex hormone. Known as 'endocrine disruptors' because they interfere with the body's hormones, some phthalates have been shown to damage the testes and reduce sperm counts. Now they have been found in formula babymilk powder, though at levels lower than the recommended tolerable daily intake. 'There is a lot of sensationalism about phthalates,' says Dr Jean Ginsburg of the Royal Free Hospital and School of Medicine in London. 'What is not sensationalism is the problem of organic pollution, organochlorides and so on. That is fact.' 
Phthalates are just one group in a host of endocrine disruptors released into the environment by industrial processes. But which pollutants affect humans, and how, is not clear. In this week's Lancet, Ginsburg calls for 'robust epidemiological' studies into the effects of these chemicals, including research into variations in sperm count in different countries.
But sperm counts can be influenced by many factors - frequency of intercourse, for example - and so are not reliable as a measure of fertility. In the same issue of the Lancet, Dr Michael Joffe of St Mary's Hospital Medical School, London compares fertility in Finland and Britain using 'time to pregnancy' (TTP) as his measure. The average sperm quality, or concentration, among Finnish men has been estimated at almost double the global average. But TTP, the time taken to conceive, reflects the biological fertility of both partners, and is, in Joffe's opinion, the most sensitive if not an infallible measure of fertility.
His comparison confirms that fertility is higher in Finland than in Britain. 'One possible factor could be that smoking rates among Finnish women have been clearly lower than for women elsewhere,' says Joffe. Although the evidence is not yet clear, maternal smoking could affect the fertility of developing offspring.

Source: Royal Free Hospital, BMJ

OUR STOLEN FUTURE
by Theo Colborn, John Peterson and Dianne Dumanoski
Published by Little Brown and Company,
306pp, £18.99