Excretion of polycyclic aromatic hydrocarbon metabolites (OH-PAHs) in cattle urine in Ghana

Abstract

Previous studies of polycyclic aromatic hydrocarbons (PAHs) in particulate matter, soils and livers of wild rats indicated that the city centre of Kumasi, Ghana has been severely polluted with high cancer potency. Cattle urine were therefore collected from Kumasi (urban) and Offinso (rural), Ghana: to determine concentrations of urinary PAH metabolites (OH-PAHs); and find their association with sex; and to estimate exposure of cattle to PAHs from the different sites. From the results, geometric mean concentrations (adjusted by specific gravity), GM, showed that 2-OHNaphthalene (2-OHNap) was the most abundant OH-PAH in cattle urine from all study sites, and naphthalene-containing-mothballs might have contributed significantly to the levels. There was no significant difference between urinary OH-PAHs concentrations in cattle from urban and rural sites except for 2-OHPhe and 4-OHPhe, and similar to urban areas, rural sites could also be polluted with PAHs. GM of 2-OHNap in cattle urine in Kokote (21.9 ± 6.51 ng/mL; a rural area), was significantly higher compared to the other sites followed by Oforikrom (4.15 ± 4.37 ng/mL; urban). The GM concentration (ng/mL) of the sum of OH-PAHs decreased in the order, Kokote (44.7) > Oforikrom (7.87) > Saboa (6.98) > Santasi (6.68) > and Twumasen Estate (5.23). The high concentrations of urinary 2-OHNap, 2-3-OHFlu, 2-OHPhe, 3-OHPhe and 4-OHPhe in Kokote indicated high PAHs exposure to cattle in this area or different/specific source of PAHs exposure. GM of 2-OHNap was significantly higher in male cattle compared to females while 1-9-OHPhe was significantly higher in females.

Oxidative stress and respiratory symptoms due to human exposure to polycyclic aromatic hydrocarbons (PAHs) in Kumasi, Ghana

“…Extraction of OH-PAHs from human urine was done according to method described by Bortey-Sam et al (2016) with slight modification. Briefly, 20 µL each of β-glucuronidase (bovine liver, type B-1; 1240 U/mg; Sigma Aldrich) and arylsulfatase (limpets Type V; 34 units/mg; Sigma Aldrich) enzymes, and 5 mL of 0.1 M sodium acetate buffer (pH 5.6) were added to 5 mL urine sample after spiking with three PAH internal standards (13C6-2-OHFluorene, 3-OHPhenanthrene-d9, and 13C6-1-OHPyrene).…”

“…Naphthalene is most likely the primary ingredient of mothballs in Ghana (Soghoian et al 2012) and is frequently used in water purification (Soghoian et al 2012), and insect repellent both in and outdoors (Bortey-Sam et al 2016). In a study by Soghoian et al…”

“…Again, in the city centre of Kumasi, high concentrations of PAHs were detected in the livers of wild rats and naphthalene was detected in 80% of livers (Bortey-Sam et al 2015b). Cattle urine was further used as a "biological indicator" to assess human risk in Kumasi and high levels of urinary OH-PAHs were detected and 2-hydroxy naphthalene was most abundant (Bortey-Sam et al 2016).…”

Sex and site differences in urinary excretion of conjugated pyrene metabolites in the West African Shorthorn cattle

“…These activities and many more could lead to deterioration of the environment and pollution likely to reach disturbing levels [ 8 ]. Some of these activities and combustion processes have caused an increase in the levels of PAHs and its metabolites in both environmental and biological samples in Kumasi [ 4 , 5 , 6 , 7 , 8 ].…”

“…Cattle is reported to excrete large amount of PAH metabolites due to high intake or exposure to the parent compound [ 33 ]. In addition to inhalation, feed is one of the dominant sources of cattle’s exposure to PAHs [ 6 , 13 ]. In previous studies, high levels of 1-OHPyr was detected in cattle urine in rural and urban sites of Ghana.…”