Tissue distribution of perfluoroalkyl acids and health status in wild Mozambique tilapia (Oreochromis mossambicus) from Loskop Dam, Mpumalanga, South Africa

Abstract

This study examined concentrations of 15 perfluoroalkyl acids (PFAAs) in tissues from male Mozambique tilapia (Oreochromis mossambicus) collected at Loskop Dam, Mpumalanga, South Africa in 2014 and 2016. Nine of the 15 PFAAs were detected frequently and were included in statistical analysis and included two of the most commonly known PFAAs, perfluorooctanesulfonic acid (PFOS) (median, 41.6ng/g) and perfluorooctanoic acid (PFOA) (median, 0.0825ng/g). Of the tissues measured, plasma (2016 and 2014 median, 22.2ng/g) contained the highest PFAA burden followed by (in descending order): liver (median, 11.6ng/g), kidney (median, 9.04ng/g), spleen (median, 5.92ng/g), adipose (median, 2.54ng/g), and muscle (median, 1.11ng/g). Loskop Dam tilapia have been affected by an inflammatory disease of the adipose tissue known as pansteatitis, so this study also aimed to investigate relationships between PFAA tissue concentrations and incidence of pansteatitis or fish health status. Results revealed that healthy tilapia exhibited an overall higher (p-value<0.05) PFAA burden than pansteatitis-affected tilapia across all tissues. Further analysis showed that organs previously noted in the literature to contain the highest PFAA concentrations, such as kidney, liver, and plasma, were the organs driving the difference in PFAA burden between the two tilapia groups. Care must be taken in the interpretations we draw from not only the results of our study, but also other PFAA measurements made on populations (human and wildlife alike) under differing health status.

A rapid and simple method to quantify per- and polyfluoroalkyl substances (PFAS) in plasma and serum using 96-well plates

“…These compounds are present in a wide variety of consumer products, including but not limited to fast food packing, textiles, clothing, pesticides, firefighting foams and stain resistant materials [1 , [3] , [4] , [5] , [6] . Once an individual is exposed to these chemicals, these chemicals bind to blood proteins and accumulate in the blood and blood-rich tissues, such as the kidney and liver [4] , [5] , [6] , [7] , [8] , [9] , [10] , [11] , [12] , [13] . For biological interrogation of PFAS exposure, analyses are typically carried out in blood matrices (e.g., plasma), blood rich tissues (e.g., liver); however, PFAS have been readily detected in other biological matrices, as well as several types of environmental matrices, including surface water, soil and sediments [14] .…”

Environmental Health Research in Africa: Important Progress and Promising Opportunities

“…Across the reviewed studies, perfluoroalkyl acids (PFAAs) were measured in water, sediment, and fish in Lake Tana, Ethiopia (Ahrens et al, 2016), in tilapia in South Africa (Bangma et al, 2017), and in wastewater and sludge from selected wastewater treatment plants in Kenya (Chirikona et al, 2015). Another study measured PFCs in maternal serum and cord blood of South African women-infant pairs.…”

A histological evaluation of pansteatitis‐affected Mozambique tilapia, Oreochromis mossambicus (Peters 1852), from different geographical locations in South Africa

“…In addition to crocodiles, this disease has been documented in the serrated hinged terrapin Pelusios sinuatus (Smith, 1838) (Huchzermeyer, Govender, Pienaar, & Deacon, 2011; Oberholster, Myburgh, Ashton, Coetzee, & Botha, 2012), fish species such as the African sharptooth catfish ( Clarias gariepinus (Burchell, 1822), the rednose labeo ( Labeo rosae Steindachner, 1894)), the Mozambique tilapia ( Oreochromis mossambicus (Peters, 1852))(Huchzermeyer, 2012a; Huchzermeyer et al., 2011, 2017; Huchzermeyer, Osthoff, Hugo, & Govender, 2013; Truter, Wyk, Oberholster, Botha, & Luus‐Powell, 2014) and various piscivorous birds (Myburgh & Botha, 2009; Oberholster, 2009) inhabiting the Olifants River System. Clinicopathological manifestation of pansteatitis includes adipose tissue necrosis, histiocytic inflammation and ceroid accumulation within granulomata and cytoplasm of aggregated macrophages, with severe cases resulting in the immobility and death of the affected host (Bangma et al., 2017; Huchzermeyer, 2012a, 2012b; Myburgh & Botha, 2009; Orós, Monagas, Calabuig, Luzardo, & Camacho, 2013). Environmental forms of pansteatitis have been linked to deleterious water conditions in conjunction with a deficiency in plasma vitamin E (Huchzermeyer, 2012a, 2012b; Huchzermeyer et al., 2013, 2017; Lane et al., 2013), selenium (Huchzermeyer, 2012a; Lane et al., 2013) and nutritional deficiencies associated with the ingestion and metabolism of large quantities of polyunsaturated lipids under oxidative conditions (Huchzermeyer et al., 2017).…”

“…A confounding feature of pansteatitis‐related deaths is the heterogeneous distribution of the disease throughout the Olifants River System (Bangma et al., 2017; Huchzermeyer et al., 2017). Currently, there are no reports available that highlight the prevalence and severity of pansteatitis in fish species within the Olifants River System.…”

“…More information is critically needed to characterize the disease in the system (Bowden, Cantu, et al, 2016). To establish the aetiology of the disease, the pathology of various body tissues has been examined in pansteatitis‐affected African sharptooth catfish (Huchzermeyer et al., 2017) and Mozambique tilapia (Bangma et al., 2017; Bowden, Cantu, et al, 2016; Bowden, Somerville, et al, 2016; Dabrowski et al., 2017; Truter et al., 2014) from Lake Loskop and sharptooth catfish from waterbodies in close proximity to and within the KNP (Huchzermeyer, 2012a, 2012b; Huchzermeyer et al., 2011, 2013, 2017). Besides research by Huchzermeyer (2012a, 2012b) and Huchzermeyer et al.…”