Characteristics of Microplastics and Their Affiliated PAHs in Surface Water in Ho Chi Minh City, Vietnam

Abstract

Microplastic pollution has become a worldwide concern. However, studies on the distribution of microplastics (MPs) from inland water to the ocean and their affiliated polycyclic aromatic hydrocarbons (PAHs) are still limited in Vietnam. In this study, we investigated the distribution of MPs and PAHs associated with MPs in canals, Saigon River, and Can Gio Sea. MPs were found at all sites, with the highest average abundance of MPs being 104.17 ± 162.44 pieces/m3 in canals, followed by 2.08 ± 2.22 pieces/m3 in the sea, and 0.60 ± 0.38 pieces/m3 in the river. Fragment, fiber, and granule were three common shapes, and each shape was dominant in one sampling area. White was the most common MP color at all sites. A total of 13 polymers and co-polymers were confirmed, and polyethylene, polypropylene, and ethylene-vinyl acetate were the three dominant polymers. The total concentration of MPs-affiliated PAHs ranged from 232.71 to 6448.66, from 30.94 to 8940.99, and from 432.95 to 3267.88 ng/g in Can Gio sea, canals, and Saigon River, respectively. Petrogenic sources were suggested as a major source of PAHs associated with MPs in Can Gio Sea, whereas those found in Saigon River and canals were from both petrogenic and pyrogenic sources.

Riverine Microplastic Pollution in Vietnam: A Review of Current Scientific Knowledge and Legal Policies

“…discharge into the river estimated at 200,000 m 3 d -1 ; [37]) at that time were an important source of fiber contamination in the Saigon River and its canal system. The tendency of higher concentrations observed in the denser urban zone with low wastewater treatment capacity was confirmed in the same system [31][32]. It was also evidenced in the Red River system with a tendency of decreasing concentrations of microplastics in the Day River surface water from places with high population density to low population density [38] and in the Bach Dang Estuary with decreasing concentrations towards the estuary mouth probably due to water mixing with seawater [35].…”

Fire and Oil Led to Complex Mixtures of PAHs on Burnt and Unburnt Plastic during the M/V X-Press Pearl Disaster

“…To contextualize the PAH content of the spilled plastic, we compared our results to the PAH content measured and reported in the literature from 19 studies of plastic pellets (317 data points) and 15 studies of plastic debris (198 data points) found globally in the marine environment (Figure ). ,,− When they arrived onshore on May 25, 2021, the white nurdles had an EPA16 PAH content (∼1260 ng/g) double the median for nurdles found globally in the marine environment (∼589 ng/g). It should be noted that many of these other studies examined nurdles with a yellowness index of 30 to 50, assuming that the yellowing indicated that these nurdles had been in the environment long enough to accumulate significant amounts of PAHs .…”

“…Comparison of PAH content for the plastic spilled during the M/V X-Press Pearl disaster analyzed in this study and plastic found in the ocean globally. Ranges of pollution level are those defined according to Yeo et al Data presented for the nurdles and plastic debris were collated from literature-reported absolute, mean, or median values, ,,− details of which are available in Table S13. A comparison of each study is included in Figure S8.…”

Occurrence of Microplastics in Drinking Water in South East Asia: A Short Review

“…Microplastic pollution is also prevalent in the region's freshwater ecosystems, which are essential for providing clean water for drinking and irrigation [6,7]. Several studies have found significant levels of MPs in freshwater sources across Southeast Asia, such as the Citarum River in Indonesia and the Saigon River in Vietnam [8,9].…”

“…Thailand has implemented a plastic bag ban, and Indonesia has pledged to reduce marine plastic debris by 70% by 2025. The Association of Southeast Asian Nations (ASEAN) has launched a framework for action on marine debris, highlighting the importance of reducing plastic waste and promoting sustainable waste management practices in the region [7][8][9].…”