This study collected male Mozambique tilapia (Oreochromis mossambicus) from Loskop Dam, Mpumalanga, South Africa in 2014 and 2016 to investigate the levels of 15 perfluoroalkyl acids (PFAAs) across six tilapia tissues. Nine of the 15 PFAAs were detected frequently and included in statistical analysis (PFOS (median, 41.6 ng/g), PFDA (median, 4.54 ng/g), PFNA (median, 1.55 ng/g), PFUnA (median, 1.41 ng/g), PFDoA (median, 1.41 ng/g), PFOSA (median, 0.768 ng/g), PFHxS (median, 0.553 ng/g), PFTriA (median, 0.250 ng/g), PFTA (meidan, 0.210 ng/g), PFOA (median, 0.083 ng/g)). Of the tissues measured plasma (2016 and 2014 median, 22.2 ng/g) contained the highest burden of measured PFAAs followed by (in descending order): liver (median, 11.6 ng/g), kidney (median, 9.04 ng/g), spleen (median, 5.92 ng/g), adipose (median, 2.54 ng/g), and muscle (median, 1.11 ng/g). Loskop Dam tilapia have been affected by an inflammatory disease of the adipose known as pansteatitis, so this study also aimed to investigate the effect of pansteatitis or health status on PFAA tissue levels in the tilapia. Statistical tests revealed a striking difference (p-value, 0.019) with healthy tilapia maintaining an overall higher PFAA burden than pansteatitis-affected tilapia across all tissues. A deeper look found that the organs previously noted in the literature that traditionally contribute to the bulk of PFAA burden, such as the kidney, liver, and plasma, were the organs driving the difference in PFAAs in the two tilapia groups. With such striking results that ran counter to expectations, care must be taken in the conclusions we draw from not only the results of our study, but also other PFAAs measurements made on populations (human and wildlife alike) of various health statuses.
Citation: Journal of Environmental Sciences-China
Pub Type: Journals
Perfluoroalkyl acids, Mozambique tilapia, liquid chromatography mass spectrometry, pansteatitis, PFOS