Levels of 17β steroid and alkylphenol estrogenic endocrine disrupting compounds in Nairobi river

Abstract

Water polluted with endocrine disrupting compounds (EDCs) has been demonstrated to cause reproductive problems in humans and wildlife. Rivers flowing through urban settlements have been shown to contain contaminated discharges from domestic, agricultural and industrial sources. Such discharges are suspected to have high levels of EDCs. The residents living along the riparian of rivers in urban settlements tend to use the water of such rivers for farming to enhance their household incomes. Together with vegetable farming, the residents also keep animals such as pigs. This practice has been noticed within the riparian of the Nairobi River, which is heavily polluted and in some places, resembling sewage sludge. The Nairobi river situation was suspected to expose humans, who consume either the vegetables and/or the animals to effects of EDCs. More direct are the effects of known EDCs, like alkyl phenol and 17β estradiol, on the animals raised using the polluted water. Our previous studies noted that boars raised using the Nairobi River had high prevalence of retained testes and high incidence of testicular histopathology. To test if such effects were caused by EDCs within the water, samples were obtained to determine the levels of these two compounds. Samples were collected from Nairobi River along informal settlements of Kibera, Dandora and Mathare using glass amber bottles and transported to the laboratory at 4ºc. Water was then analyzed to determine the pollution levels of two known EDCs (17β steroid and alkylphenol) using Gas chromatography-Mass Spectrophotometry. The levels of alkylphenol and 17β estradiol in the sampled water were between 0.08 to 0.917µg/L and below detection limit (BDL) to 0.3005 µg/L for 17β –estradiol alkylphenol, respectively. The mean values were 0.0953µg/L and 0.360µg/L for 17β steroid and alkylphenol, respectively. The detected levels of 17β steroid and alkylphenol point towards a suggestion that the effects observed in the boars raised along such riparian are caused by estrogenic endocrine disrupting coumpounds and the need to have a policy in place to control effects of such EDCs like 17β estradiol and alkylphenol on humans and/or animals.