Partitioning and Bioaccumulation of Legacy and Emerging Hydrophobic Organic Chemicals in Mangrove Ecosystems

Abstract

Knowledge regarding partitioning behavior and bioaccumulation potential of environmental contaminants is important for ecological and human health risk assessment. While a range of models are available to describe bioaccumulation potential of hydrophobic organic chemicals (HOCs) in temperate aquatic food webs, their applicability to tropical systems still needs to be validated. The present study involved field investigations to assess the occurrence, partitioning, and bioaccumulation behavior of several legacy and emerging HOCs in mangrove ecosystems in Singapore. Concentrations of synthetic musk fragrance compounds, methyl triclosan (MTCS), polychlorinated biphenyls, organochlorine pesticides, and polycyclic aromatic hydrocarbons were measured in mangrove sediments, clams, and caged mussels. Freely dissolved concentrations of the HOCs in water were determined using silicone rubber passive samplers. Results showed that polycyclic musks and MTCS are present in mangrove ecosystems and can accumulate in the tissues of mollusks. The generated HOC concentration data for mangrove water, sediments, and biota samples was further utilized to evaluate water–sediment partitioning (e.g., K oc values) and bioaccumulation behavior (e.g., BAF and BSAF values). Overall, the empirical models fit reasonably well with the data obtained for this ecosystem, supporting the concept that general models are applicable to predict the behavior of legacy and emerging HOCs in mangrove ecosystems.

Levels and trends of synthetic musks in marine bivalves from French coastal areas

“…The presence of a stable transformation product of HHCB, HHCB-lactone, has been reported in biota (Lange et al, 2015;Trabalón et al, 2015), but its use as a tracer for metabolism warrants further research as it can also originate in the environment by chemical, photochemical and/or microbiological processes. In marine bivalves, similar bioaccumulation factors for HHCB and AHTN have been reported for Lokan clams (Polymesoda expansa) and Asian green mussels (Perna viridis) (Bayen et al, 2019). HHCB and AHTN were also found to correlate regardless of the species (Perna viridis, Mytilus edulis.)…”

“…There is a general agreement on the finding of ratios close to 1 in air and background sites primarily under influence of atmospheric depositions, where AHTN is more stable to atmospheric oxidation processes (Lange et al, 2015;McDonough et al, 2016;Xie et al, 2007). When comparing sediments and water, some authors have reported ratios closer to 1 in sediments, primarily due to a stronger tendency of AHTN for sorption and/or a degradation of HHCB into its lactone derivative in sediment (Bayen et al, 2019;Heberer, 2002;Lu et al, 2015).…”

Applications for Passive Sampling of Hydrophobic Organic Contaminants in Water—A Review

“…The influence of matrix complexity (organic matter) on dissolved HOC concentrations was investigated in lab exposures [174]. PSDs were deployed in coastal waters and used to predict the concentrations of HOCs in other environmental compartments through equilibrium models [175,176]. PSDs have been exposed in sediments, pore waters, waters and the overlying atmosphere (gaseous and aerosol) to determine activity gradients across environmental compartments [177][178][179][180][181][182][183][184][185].…”

Chemical pollution as a driver of biodiversity loss and potential deterioration of ecosystem services in Eastern Africa: A critical review

“…7 Therefore, it follows that biodiversity loss and ecosystem services are closely related, and have the potential to affect both human health and global economies. 10 Because the spread of chemical pollutants in the environment represents a serious concern for ecosystem health 11 , holistic approaches such as One Health and Eco-Health have emerged in the last few years. Both these approaches assume that humans, animals, and the ecosystems to which they belong interact in a complex way and at different levels.…”

“…Such activities involve the release of ubiquitous environmental chemical pollutants such as organochlorine compounds (OCs) and heavy metals. 11,19 It follows that chemical pollution is a global emergency concerning the health of all the different ecosystem components, i.e. environment, animals, humans.…”