Distribution characteristics and risk assessment of heavy metals in seawater, sediment and shellfish in the inner and outer Daya Bay, Guangdong

Abstract

We investigated the distribution, sources, and ecological risks of heavy metals (As, Hg, Zn, Cd, Pb, Cu, and Cr) in seawater, sediments, and shellfish in the inner and outer waters of Daya Bay. 42 seawater quality survey sites, 21 sediment survey sites and 21 biological survey sites were set up in the study area. Our results showed that Daya Bay’s seawater is both clean and has a high Cu exceedance factor. The sediment heavy metal potential ecological hazard indices are all less than 40, which indicates a minimal degree of risk. ERI in the bay (mean value of ERIis 25.43) and that outside the bay (mean value of 23.56) is lower than 150, so the potential impact on the ecosystem is relatively low. In the Bay, Hg and Zn are primarily from fossil fuel and coal combustion, which enter the ocean via dry and wet deposition or surface runoff. Outside the Bay, Cr, Cu, Zn and Pb are derived the combustion waste gases of ships that enter the ocean via atmospheric deposition. Concerningly, arsenic and lead level in shellfish organisms appear to be above the standard values.However, because THQ and TTHQ are less than 1, there is no potential risk to human health. The weekly assessed intakes (EWIs) of Hg, AS, Pb, and Cd in shellfish inside and outside Daya Bay were 0.093 (0.058 outside the Bay), 0.594 (0.534), 1.115 (1.489), and 0.201 (0.190), respectively, all of these values were lower than the provisional PTWI for humans established by WHO. This indicates that the probability of carcinogenic risk to the population from heavy metals in shellfish are all below unacceptable levels.

Distribution and Probabilistic Risk Assessment of Antibiotics, Illegal Drugs, and Toxic Elements in Gastropods from Southeast China

“…This underscores that toxic elements in gastropods from southeast China present a higher health risk than antibiotic residues. The pollution of toxic elements in the marine ecosystem is a global challenge with implications for public health [42,43]. Additionally, we observed higher percentages of Cd and As THQs in the children group than in other groups.…”

Bioremediation of propylbenzenes by a novel marine microalga Rhinomonas reticulata S6A isolated from Daya Bay: acute toxicity, growth kinetics and biodegradation performance

“…Accordingly, in this study, the 28 stations were set up in the three sea areas near China, with the coasts corresponding to different ports, industrial bases, or inland river estuaries (Figure 1, Table S1), to screen for candidate species. The ecological environment of Daya Bay, a semienclosed shallow bay located in the northern part of the South China Sea, has been significantly affected by human activities (Yu et al, 2022). The eastern part of the Daya Bay petrochemical base releases organics into the surrounding environment throughout the year, thereby improving the tolerance of organisms in the nearby sea area to pollutants (Wu et al, 2010).…”