Global warming spurs spread of toxic bugs, says study

Global warming may be spurring the spread of Cyanobacteria, one of the most primitive of bugs, while causing them to produce greater amounts of toxins, which may affect liver, nervous system and eyes, according to a study.

"These toxins may affect the liver and other organs (hepatotoxins), the nervous system (neurotoxins), different cells (cytotoxins), the eyes and mucous membranes, as well as causing dermatitis and allergies," explains Francisca F. del Campo, study co-author and researcher at the Autonomous University of Madrid.

"We suspect that these cytotoxins may be behind some gastrointestinal disorders and other illnesses, but epidemiological studies are required to confirm this," says Del Campo, the journal Water Research reports.

"Cyanobacteria love warm water, therefore an increase in temperature during this century may stimulate their growth, especially that of the cytotoxic varieties, which could even produce more toxins and become more harmful," says study co-author Rehab El-Shehawy, from the Instituto Madrileno de Estudios Avanzados (IMDEA), Spain.

El-Shehawy's team is working on developing efficient tools to monitor the number of cyanobacteria (which once helped oxygenate the earth's atmosphere) in water, according to a statement of FECYT (Spanish Foundation for Science and Technology).

Blooms of these micro-organisms in lakes, reservoirs and rivers all over the world and in estuaries and seas, such as the Baltic, are becoming a more and more frequent phenomenon. Experts say this poses an economic problem - as it affects water sanitation, shipping and tourism, for example - and an environmental problem.

In Spain, the relation between the proliferations of toxic cyanobacteria in the Donana wetlands and the death rate of wild fauna in this natural space has been confirmed, but of even more concern are its impact on human health.