Cyanobacteria are aquatic microorganisms that thrive best in warm waters. Global warming has been linked to the exponential growth of these microorganisms in natural waters that poses a serious threat to human health. These microorganisms can produce toxins harmful to the cells, nervous system, liver and other organs in the body.
Rehab El-Shehawy expressed concerns on the environmental and economic repercussions of the prolific growth of cyanobacteria. El-Shehawy is a co-author of a study on the effect of warmer temperatures on the growth of these microorganisms.
Cyanobacteria blooms in rivers, lakes, reservoirs, estuaries and seas are becoming frequent occurrences due to the rise of water temperatures from global warming. These can cause economic problems in relation to water sanitation, shipping and tourism.
Environmental problems arising from threats to the ecosystem are likewise a concern. In Spain, it was confirmed that the proliferation of cyanobacteria in the Doñana wetlands caused the death of local wildlife.
Health threats of cyanobacteria arise from the production of various toxins by different species of the microorganism. According to Francisca F. del Campo, these toxins can be hepatotoxins (harmful to the liver), neurotoxins (harmful to the nervous system) and cytotoxins (harmful to different types of cells). Del Campo is also a co-author of the study published in Water Research with El-Shehawy.
The researchers are calling for increased public attention on the serious threats posed by cyanobacteria. In particular, del Campo calls for epidemiological studies to relate incidences of gastrointestinal disorders to high levels of cytotoxins in water reservoirs.
Analysis conducted by the Centre for Studies and Experimentation of Public Works (CEDEX) revealed around 20 percent of Spanish reservoirs had cyanobacteria levels exceeding 2 mm3/L, which is the permissible level set by WHO for bathing water. In this group, 45 percent of the sampled reservoirs had concentrations of microcystins (a hepatotoxin) above 1 microgram per liter, which is the permissible level set by WHO and the Spanish government for bathing water.