Abstract:
Endocrine disrupting chemicals (EDCs) are ubiquitous in the environment and have
been detected in drinking water. Although various water treatment processes can
remove EDCs, chemicals can migrate from pipes that transport water and
contaminate drinking water. Globally bottled water consumption is steadily rising as
an alternative to tap water, but EDCs have also been detected in bottled water.
Sources of EDCs in bottled water include contamination of the water source,
contamination through the production process or the migration of EDCs from the
packaging material. There is limited information on EDCs in drinking water and
bottled water from South Africa.
The aim of this study was to determine the estrogenic activity, levels of selected
EDCs and the potential health risks associated with the consumption of water from
selected distribution points in Pretoria (City of Tshwane) and Cape Town as well as
bottled water. The study consisted of 3 phases. Phase 1 included the analysis of
drinking water samples from ten water distribution points in Pretoria and Cape Town
collected over four sampling periods. In phase 2, ten brands of bottled water were
analysed after exposure to different storage conditions (20°C, 40°C, light and dark)
for 10 days. Samples were extracted using a C18 solid phase extraction method.
Estrogenic activity was assessed using the recombinant yeast estrogen screen
(YES) bioassay and the T47D-KBluc reporter gene bioassay. The extracts were
analysed for di(2-ethylhexyl) adipate (DEHA), di(2-ethylhexyl) phthalate (DEHP),
diisononylphthalate (DINP), dibutyl phthalate (DBP), bisphenol A (BPA),
nonylphenol (NP), 17β-estradiol (E2), estrone (E1) and ethynylestradiol (EE2) using
UPLC-MS. Phase 3 consisted of a scenario based health risk assessment to assess
the carcinogenic and toxic human health risks associated with the consumption of
distribution point and bottled water.
All the samples were below the detection limit (dl) in the YES bioassay, but
estrogenic activity was detected in bottled and distribution point water using the
T47D-KBluc bioassay. All samples were below the 0.7 ng/L trigger value for
estrogenic activity in drinking water. NP was below the dl for all the samples, E2 was detected in five distribution point samples and E1, EE2, DEHA, DEHP, DINP, DBP
and BPA were detected in distribution point and bottled water samples. The
estrogenic activity and levels of target chemicals were comparable to the levels
found in other countries.
Hazard quotients for BPA, DEHA and DINP were higher in bottled water compared
to distribution point water. The greatest non-carcinogenic health risk was posed by
E1 in distribution point water from Pretoria and the highest cancer risk by levels of
DEHP in distribution point water from Cape Town. However, overall, health risk
assessment revealed acceptable health and carcinogenic risks associated with the
consumption of distribution point and bottled water.
Although the potential health risks posed by the EDCs found in the water samples in
this study were low, the fact that potential EDCs were found in the water samples are
still of concern. A monitoring strategy that also includes water from other
municipalities and other brands of bottled water are therefore recommended.
