River pollutants are turning fish in Malaysian rivers “gay” and even “transsexual” by changing their hormones which, in turn, affect their sex, according to an expert.
KUALA LUMPUR — As the authorities struggle to stop runaway river pollution and water cuts, an expert has warned that Malaysians are facing a new threat in their water supply for which no one is prepared.
These pollutants, called endocrine disruptors (EDCs), are turning fish in Malaysian rivers “gay” and even “transsexual” by changing their hormones which, in turn, affect their sex, said hydro-chemistry expert Prof Ahmad Zaharin Aris.
According to the United States Environmental Protection Agency (EPA), there is growing evidence that humans and animals have “exhibited adverse health consequences from exposure to environmental chemicals that interact with the endocrine system”.
These effects include increased risk of getting cancer and developing reproductive problems in adults and growth defects in children, according to the EPA.
These chemicals, which disrupt the human endocrine system, are already present in local drinking water and food supply, said Mr Zaharin of Universiti Putra Malaysia (UPM).
The endocrine system regulates hormones in the human body which, in turn, affect growth, development and reproduction.
EDCs are discharged from the pharmaceutical and cosmetics industries while producing consumer items, such as deodorants, cleansers and medicines.
It is also discharged from consumers who use these items, Mr Zaharin said.
In studies by UPM’s environmental studies faculty in some of the country’s water sources, Mr Zaharin said EDCs had caused extraordinary sex changes in fish.
“They changed fish sexual preferences by disrupting their hormones so that males become attracted to males and females to females. In essence, gay and lesbian fish,” Mr Zaharin told a seminar on river pollution organised by national water industry regular SPAN.
“There are also fish born with opposite reproductive organs, such as male fish with female organs and vice-versa. So when we eat too much of these fish, they can accumulate in our bodies.”
The sex changes in fish and shell fish are due to active ingredients used in the production of family planning pills, he said.
SPAN or the Water Services Commission is drawing up plans to address persistent river pollution that has led to water cuts in Selangor and sickened 6,000 people in Pasir Gudang, Johor.
Water experts consider EDCs a form of “emerging pollutants”, which are new chemicals and effluents found in increasing quantities in the environment.
Micro-plastics, which are smaller than a grain of rice, are another form of emerging pollutant.
SPAN chairman Charles Santiago said emerging pollutants are one of the biggest new challenges facing the water industry.
These are unlike conventional pollutants like heavy metals, where studies are ongoing to learn their long-term effects on humans and how to deal with them, Mr Zaharin said.
He added that there are about 40,000 of these new emerging pollutants of which only a few hundred have been identified.
“Consumers need to be aware of the dangers of emerging pollutants and to minimise contact with them.
“For instance, stop drinking too much water from plastic bottles but drink from glass or your tumbler. We can’t 100% eliminate the risk but we can minimise it.
“If you eat fish regularly, then you need to minimise this also. An 80kg adult may be able to safely eat 1kg of fish but children may not be able to tolerate this much. Everyone has different acceptance levels.”