Occurrence and removal of drugs and endocrine disruptors in water supply systems in the metropolitan region of Belo Horizonte -Minas Gerais State, Brazil-.

Abstract

This study evaluates both the occurrence and removal of 24 compounds, including drugs and endocrine disruptors, in 8 water treatment plants (WTP) located in the metropolitan region of Belo Horizonte (Minas Gerais State, Brazil). The compounds 4-nonylphenol,

4-octylphenol, 17α-ethinylestradiol, 17β-estradiol, acy- clovir, bisphenol A, bezafbrate, cafeine, dexamethasone,

diclofenac sodium, diltiazem, estrone, estriol, gemfbro- zil, ibuprofen, linezolid, loratadine, losartan, metformin,

naproxen, paracetamol, promethazine, propranolol and sulfamethoxazole were monitored at 3 sampling points

(raw water, fltered water, treated water) over 10 or 12 col- lection campaigns for each WTP. The results showed that

bisphenol A occurred at higher concentrations during the dry period with a maximum concentration of 3257.1 ng L−1, while the compounds 4-nonylphenol and losartan exhibited higher concentrations in the rainy period with maximum concentrations of 8577.2 ng L−1 and 705.8 ng L−1, respectively. Regarding the removal of compounds

in the monitored WTPs, the clarifcation step demon- strated better removals for 4-nonylphenol, bisphenol-A,

paracetamol, and sulfamethoxazole, whereas the disinfec- tion step mainly removed the compounds 4-octylphenol

and estrone. Margin of exposure (ME) assessment results indicated that only dexamethasone, ethinyl estradiol,

diclofenac, estradiol, and estrone were classifed as immi- nent risk or alert considering the 95th percentile concen- tration found in the samples of treated water.