Occurrence, Species, and Organ Differences in Bioaccumulation Patterns of Phthalate Esters in Municipal Domestic Water Supply Lakes in Ibadan, Nigeria

Abstract

The occurrence of phthalate esters (PE) was examined in biota, ambient water, and sediments of two man-made lakes (Asejire and Eleyele) in southwestern Nigeria. Five fish species (Tilapia zillii, Hepsetus odoe, Parachanna obscura, Chrysichthys nigrodigitatus, and Mormyrus rume) were analyzed for PE levels and used for calculating bioconcentration factors (BCF) and biota-sediment accumulation factors (BSAF). In addition, measured PE levels were thereafter used to calculate the phthalate pollution index (PPI) in biota and the environment. At both lakes, all sampled species had k-factor > 1, showing apparently normal growth and health condition. Higher PE levels were found in sediments compared with water at both lakes, with a pattern showing that di(2-ethylhexyl) phthalate (DEHP) was predominant PE. While there were no unique patterns of PE concentrations in both lakes, differences were observed in organ concentration patterns that were evident at both lakes. For T. zillii, the BSAF was higher for dibutyl phthalate (DBP) compared to diethyl phthalate (DEP) and lowest for DEHP. The concentration pattern demonstrated that DBP concentrated more in gills (BCF: 6.7), while DEHP concentrated more in liver (BCF: 15.2) of T. zillii at Asejire. At Eleyele, T. zillii liver and gills concentrated less DEP and DEHP. The PPI value was significantly higher in sediment with respective values of 0.27 and 0.44 at Asejire and Eleyele lakes compared with water with respective values of 0.1 and 0.18 at Asejire and Eleyele lakes. Overall, our findings suggest a broader environmental and human health implication of high PE levels in these lakes, since they provide vast water volumes that are used for municipal domestic water supply. Further, these lakes support intense artisanal fisheries, representing significant sources of aquatic food resources for neighboring communities.

Xenobiotic biotransformation, oxidative stress and obesogenic molecular biomarker responses in Tilapia guineensis from Eleyele Lake, Nigeria

“…In addition, the Fisheries division of the Ministry of Agriculture and Natural Resources in Oyo State, Nigeria took over the management of fishing activities in the Lake with the aim of encouraging intensive artisanal fisheries. Herein, trace metals and PAHs were shown to accumulate in the edible tissue (muscle) of the studied fish, consistent with recently reported levels of phthalate esters (PEs) in sediments and biota at Eleyele lake (Adeogun et al, 2015). Overall, given that the Eleyele lake plays some significant roles in the livelihood of the neighboring communities through domestic water supply and fisheries, the high concentration and occurrence of PAHs, trace metals and other environmental contaminants measured in edible fish should be viewed as significant health concerns.…”

“…Recently, we reported that di-isodecyl phthalate (DiDP) bound with high efficiency to piscine PPARs demonstrating a greater preference for RXRα, in addition to coordinated increase in the expression of PPARs and rxr-α, as well as their downstream target genes in fish in vitro system (Cocci et al, 2015). Relevant to the present data, it should be noted that we recently reported high phthalate esters (PEs) concentrations in Eleyele lake water, sediment and biota samples (Adeogun et al 2015). Further, a parallel increase in cpt1 and ppar- with triacylglycerol content in the liver of rats exposed to high fat diet was observed (Boukouvalas et al, 2010a).…”

Disruption of Intestinal Homeostasis Through Altered Responses of the Microbial Community, Energy Metabolites, and Immune System in Zebrafish After Chronic Exposure to DEHP

“…In recent years, elevated levels of DEHP have been reported in freshwater resources used for drinking and domestic utilities, and this could ultimately pose threats to environmental and human health (Adeogun et al, 2015;Luo et al, 2018). Previous studies on DEHP toxicity had mainly focused on the developmental and reproduction effects through various biological pathways in fish (Mu et al, 2018;Boran and Terzi, 2019).…”

Determination and Risk Associated with Phthalic Esters Distribution from the Ekpan River, Effurun, Delta State, Nigeria

“…PAEs in a riverine setting are now receiving worldwide interest for their distribution, source, migration, and possible ecological hazards [2], [15]. In Nigeria, Phthalates have been revealed to be in varying concentrations in river systems [16]- [21]. Other human-caused chemical compounds, including point and non-point wastewater discharge, surface runoff, and air deposition are also possible entry points for PAEs [2], [22], [23].…”