Risk assessment of human exposure to polycyclic aromatic hydrocarbons via shrimp (Macrobrachium felicinum) consumption along the Imo River catchments, SE Nigeria

Abstract

Shrimp species (Macrobrachium felicinum) collected from estuarine mangrove area of the Imo River is an important route of exposure to polycyclic aromatic hydrocarbons (PAHs). The estuarine associated sediment (EAS) composited sample showed higher TPAH, ΣAlkyl, ΣPAH and ΣPAH concentrations (550.84, 172.36, 413.17 and 482.11 ng/g dry weight-dw) than their mean concentrations in shrimp samples (509.39 ± 354.21, 31.38 ± 18.49, 52.10 ± 1.35 and 460.06 ± 330.76 ng/g wet weight-ww), respectively. Among the individual PAHs congeners, phenanthrene was the dominant species detected in the EAS accounting for 21.02 % of the total PAH load and the decreasing order of 3- > 2- > 5- > 4- > 6-ring contamination was found. A different pattern predominated by naphthalene was observed for the shrimp species, suggesting that the organisms have different selectivity for a range of PAHs congeners. These variations may be attributed to different degree of bioavailability of these compounds, characteristic sandy lithology of the EAS and the protective capacity of soot particles associated with liquid fossil fuel combustion masking the uptake of high molecular weight PAHs by the organisms. Cancer risk associated with consumption of shrimps in the region was assessed using estimated daily intake (EDI) and compared with standards. The EDI values for naphthalene, benzo(a)pyrene and ∑PAH were lower than the USEPA benchmarks and EFSA levels of concern values for adult and children population, suggesting low probability of developing cancer.

Polycyclic aromatic hydrocarbons bioaccessibility in seafood: Culinary practices effects on dietary exposure

“…However, the detected PAHs levels were very low and presented no health risks to consumers. Dosunmu et al (2016) and Hong et al (2016) described similar results. Dosunmu et al (2016) assessed the risk of human exposure to PAHs via shrimp consumption and concluded that lifetime cancer risk was unlikely for inhabitants of coastal zones that are likely to consume high amounts of shrimp species.…”

“…The geographic origin of the species was also evaluated because the bioaccumulation of PAHs mainly depends on biota feeding preference and trophic level, as well environmental contamination (Hamidi et al, 2016). When comparing our results with previous studies, the shrimp (Macrobrachium felicinum) collected in Nigeria presented fluorene values of 7.0 µg kg −1 (Dosunmu et al, 2016) i.e. about 3500 times higher than those determined for the Equator shrimp acquired in Portugal (0.2 µg kg −1 , Table 2).…”

“…The profile of PAHs in seafood depends on the environmental conditions where marine organisms grow, on their metabolic activity and biometric characteristics (López-Jiménez et al, 2014). In previous studies, phenanthrene was the dominant compound (115.8 μgkg −1 ), accounting for majority of PAHs load for shrimp (Macrobrachium felicinum) from Nigeria (Dosunmu et al, 2016) and for farm mussels (43.3 μgkg −1 ) from Italy (Mercogliano et al, 2016). Yet, in this work, phenanthrene was not detected in shrimp samples (Table 2).…”

“…Bioaccessibility tests can be carried out using in vitro models, which are simple, easy, cost-effective, provide accurate results in a short time and reduce the need of animal experimentation (Hamidi et al, 2016). Despite already validated for PAHs, only few studies employed this tool to assess these compounds bioaccessibility in seafood and its relationship with culinary practices (Dosunmu et al, 2016;Soriano et al, 2007;Wang et al, 2010;Yu et al, 2012). The bioaccessibility of PAHs from Shanghai seafood were determined in shrimp, clam, carp and croaker with shrimp presenting the lowest levels of PAHs and clam the highest levels and, revealing 47.2% of bioaccessibility on average (Yu et al, 2012).…”

“…The bioaccessibility of PAHs from Shanghai seafood were determined in shrimp, clam, carp and croaker with shrimp presenting the lowest levels of PAHs and clam the highest levels and, revealing 47.2% of bioaccessibility on average (Yu et al, 2012). Shrimps can bioaccumulate contaminants from water and sediment (Dosunmu et al, 2016), while filter feeding organisms like bivalves can absorb contaminants from water and plankton (Soriano et al, 2007). Thus, these species can be used as sentinel organisms for monitoring PAHs in the environment and may, simultaneously, be an important tool to assess human exposure to contaminants (Mercogliano et al, 2016).…”