Microplastics in Saudi Arabia: Environmental occurrence, research gaps, and challenges in extreme conditions

Microplastics (MPs) have become a prevalent environmental pollutant due to poor plastic waste management practices, posing risks to both terrestrial and aquatic ecosystems. Research on MPs has grown globally, including in Saudi Arabia, where plastic waste management is a major issue. This review examines research methods, pollution levels, and gaps in MP research in Saudi Arabia, focusing on challenges posed by extreme weather conditions. MP presence was detected in various environmental compartments, including seawater, sediments, dust, food, and beverages, with polyethylene being the most detected polymer overall. Inland samples are dominated by fibers, while seawater samples reveal higher proportions of fragments and films. Historical analyses indicate that large volumes of plastics have accumulated in mangrove sediments of Saudi Arabia since the 1930s, with accelerated burial rates since the mid-20th century. Evidence from biota shows MP ingestion by commercially important fish, particularly reef-associated species, with physiological effects also observed in laboratory exposures. Natural removal mechanisms have been documented, as giant clams actively filter MPs and coral reefs act as MP sinks in the Red Sea. Human exposure, especially among toddlers via household dust, and through consumption of food and beverages, represents an emerging health concern. Research on MPs in the Red Sea and Arabian Gulf faces significant challenges due to the extreme salinity, high temperatures, and widespread dust contamination in the region. Limited analytical capabilities and complex oceanographic conditions also make accurate sampling, detection, and characterization difficult. Although there is increasing knowledge, there are still major gaps in identifying the sources, transport methods, composition, toxicity, and ecological impacts of MPs. This highlights the critical importance of advancing detection technologies and assessing potential health risks. • Microplastics have been detected in various environmental matrices in Saudi Arabia, with polyethylene as the most dominant polymer. • Mangrove sediments show plastic accumulation dating back to the 1930s, and reef-associated fish exhibit ingestion of MPs, with laboratory studies revealing physiological effects. • Pathways of exposure include household dust, food, and beverages, with toddlers identified as a particularly vulnerable group. • AI-engineered biodegradable plastic-binding peptides (PBPs), developed in Saudi Arabia, show promise as an efficient and sustainable MP remediation technology.