Muscat – A study on the additive effects of microplastics accumulation and cadmium toxicity in male zebrafish won in the Young Researcher’s Environmental and Biological Resources category of 10th National Research Awards organised by Ministry of Higher Education, Research and Innovation.

The research was led by Maklas Said al Marshoudi, Lecturer at University of Technology and Applied Sciences, Muscat.

Elaborating on the research, Marshoudi said microplastics have emerged as contaminants of concern because of their ubiquitous presence in almost all aquatic environments. The ecological effects of microplastics are complex and depend on multiple factors, including their size and the ecological matrix. There is an urgent need for multifactorial studies to elucidate their impacts.

Marshoudi explained that there is an additive interaction between water-borne cadmium (Cd) and microplastics on bioaccumulation in males, but not in females. Cd accumulation increased twofold when water-borne Cd and microplastics were combined. Water-borne Cd induced significantly higher levels of metallothionein compared to microplastics pre-exposed to Cd.

However, Cd-treated microplastics caused greater damage to the intestine and liver compared to untreated microplastics suggesting that bound Cd could be released or modulate microplastics toxicity.

The research team also showed that co-exposure to water-borne Cd and microplastics increased anxiety in zebrafish, compared with water-borne Cd alone, suggesting using microplastics as a vector may increase toxicity. The study demonstrated that microplastics could enhance the toxicity of Cd, but further study is needed to elucidate the mechanism.

According to Marshoudi, the most important finding of this research is the ability of microplastics to increase cadmium toxicity and accumulation in the studied fish. The toxicological interaction of microplastics and other conventional toxicants is still not fully understood and there is a global need for more research in this area.

The research project was published in Chemosphere, and team, besides Marshoudi, included Dr Hassan al Raisi, Dr Aziz al Habsi and Dr Michael J Barry.

Marshoudi described the National Research Award is one that recognises hard work and dedication to environ-mental research. “The award acknowledges the importance and the critical role that researchers play in the nation’s development and prosperity.”