Microplastic contaminations in edible seaweed Caulerpa racemosa across Indonesian tropical seawaters related to land uses: Implication on human health

Edible seaweed, specifically Caulerpa racemosa, is harvested from both inland and island environments across Indonesian waters. However, recent developments and land-use changes from intact ecosystems to urbanized areas have threatened seaweed habitats through microplastic contamination. This study evaluates the abundance of microplastics in consumed seaweed from inland and island habitats, considering land-use variables and conducting health risk assessments. The results show that seaweed harvested from islands contains lower microplastic average abundance and standard deviation (1.77 ± 1.48 particles/g) than seaweed harvested from inland sources (3.56 ± 2.84 particles/g). The microplastic content in seaweed is influenced by the distance to developed areas. Additionally, fibers and fragments in the seaweed are positively correlated with human population density and size of developed areas. Based on CMPI, fragment has affected C. racemosa in island environments as well as fiber in inland areas. PE, PP, and PS are common types of polymers. Health risk assessments based on Average Daily Intake indicate that children and women are more vulnerable to these contaminants. These findings inform relevant stakeholders about the importance of considering island environments for the sustainable and healthy harvest of seaweed.