John Yeld's article on the need for a cost-benefit analysis of whale-based tourism versus the presence of a missile range on the south Cape coast (The Sunday Independent, November 2) is right on the money.

A critical omission from Yeld's commentary is the issue of pollution from missile testing. Armscor has long said that whales and missile testing can safely co-habit the same area, but emerging research from around the world into use of solid rocket fuels such as sodium perchlorate indicates otherwise.

Perchlorate is a persistent environmental toxin, and extensive contamination of groundwater and soil has occurred in the United States. It is carcinogenic and also has noted effects on thyroid gland function, especially in young people. No attention has been paid to the use of this toxic chemical in South Africa.

The effects of perchlorate on whales and wildlife should also be investigated. Clearly it will affect these mammals if found in significant amounts, and platitudes from the arms industry cannot be questioningly accepted.

It is no good rescuing whales from hunting, only to poison them slowly.

Perchlorate is evidently difficult to contain and precious little information exists about the levels of manufacture, handling or contamination of this chemical at the missile testing range or, for that matter, elsewhere in South Africa.

The effects of the use, manufacture and testing of this chemical must be properly investigated so that proper and transparent management practices can be put in place.

Our arms industry must be brought under proper environmental scrutiny.

With acknowledgements to Glen Ashton and the Sunday Independent.