Prevalence of Eight Phthalate Monoesters in Water from the Okavango Delta, Northern Botswana
Phthalate diesters are used in personal care products, plastics, and pesticides, resulting in widespread human and wildlife exposure. Phthalate diesters leach out of these products and ultimately enter biological systems where they are quickly metabolized to phthalate monoesters and glucuronides. As such, phthalate monoesters can serve as indicators of anthropogenic activity in wilderness areas. The Okavango Delta, an inland seasonal wetland covering 5000–12,000 km2 in Botswana, provides fresh water to many species of birds, fish, reptiles, and large mammals. Water samples (N = 46) were taken from across the Okavango water system, extracted, and analyzed for eight different phthalate monoesters using liquid chromatography and isotope dilution mass spectrometry. Seven of eight phthalate monoesters were detected from the low ng/L to low µg/L levels. Phthalate monoesters were found in samples from all five sampling regions. Sources of these contaminants are unknown, but their presence indicates encroachment of human activity on the Okavango Delta.
KeywordsPhthalates Okavango Delta Water River
We greatly appreciate the hospitality, guidance, and field assistance of Ineelo Mosie, Rele Sekotswe, Guy Lobjoit, Brandon Moore, Mike Murray-Hudson, Keta Mosepele and the Okavango Research Institute. Also support came from other members of the Brock research group, Emily Phillips and Michael Way; the Coypu Foundation; and the University of North Carolina Asheville.
This study was funded primarily by the University of North Carolina Asheville with additional support from the Fulbright Foundation, Coypu Foundation and the Okavango Research Institute.
Compliance with Ethical Standards
Conflict of interest
The authors declare they have no conflict of interest.
- Brock JW, Kato K, Silva MJ, Reidy JA, Malek NA, Hodge CC, Nakazawa H, Needham LL, Barr DB (2003) Quantitative detection of nine phthalate metabolites in human serum using reverse phase high performance liquid chromatography-electrospray ionization-tandem mass spectrometry. J Anal Toxicol. 27:284–289. https://doi.org/10.1093/jat/27.5.284 CrossRefGoogle Scholar
- Center for Invasive and Aquatic Plants (2018) University of Florida. https://plants.ifas.ufl.edu/ Accessed 2 Oct 2018
- Centers for Disease Control and Prevention (2018). National Center for Health Statistics (NCHS). National Health and Nutrition Examination Survey Data. Hyattsville, MD: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention (2016–2017) https://wwwn.cdc.gov/nchs/nhanes/ContinuousNhanes/ Accessed 2 Oct 2018
- Mladenov N, Wolski P, Hettiarachchi MG, Murray-Hudson M, Enriquez H, Damaraju S, Galkaduwa BM, McKnight MD, Masamba W (2013) Abiotic and biotic factors influencing the mobility of arsenic in groundwater of a through-flow island in the Okavango Delta, Botswana. J Hydr 518:326–341. https://doi.org/10.1016/j.jhydrol.2013.09.026 CrossRefGoogle Scholar
- Mmualefe LC, Torto N, Huntsman-Mapila P, Mbongwe B (2009) Headspace solid phase microextraction in the determination of pesticides in water samples from the Okavango Delta with gas chromatography-electron capture detection and time-of-flight mass spectrometry. Microchem J 91:239–244. https://doi.org/10.1016/j.microc.2008.12.005 CrossRefGoogle Scholar
- Olujimi O, Fatoki S, Odendaal J, Daso P (2012) Chemical monitoring and temporal variation in levels of endocrine disrupting chemicals (priority phenols and phthalate esters) from selected wastewater treatment plants and freshwater systems of the Republic of South Africa. Microchem J 101:11–23. https://doi.org/10.1016/j.microc.2011.09.011 CrossRefGoogle Scholar
- Parks LG, Ostby JS, Lambright CR, Abbott BD, Klinefelter GR, Barlow NJ, Gray LE Jr (2000) The plasticizer diethylhexyl phthalate induces malformations by decreasing fetal testosterone synthesis during sexual differentiation in the male rat. Toxicol Sci 58:339–349. https://doi.org/10.1093/toxsci/58.2.339 CrossRefGoogle Scholar
- Sanchez-Avila J, Bonet J, Velasco G, Lacorte S (2009) Determination and occurrence of phthalates, alkylphenols, bisphenol A, PBDEs, PCB’s an PAHs in an industrial sewage grid discharging to a Municipal Wastewaters Treatment Plant. Sci Total Environ 407:4157–4167. https://doi.org/10.1016/j.scitotenv.2009.03.016 CrossRefGoogle Scholar
- Silva M, Blount BC (2010) Laboratory Procedure Manual; Phthalate metabolites in Urine. Center for Disease Control. https://www.cdc.gov/nchs/data/nhanes/nhanes_07_08/phthte_e_met_phthalate_metabolites.pdf
- Wenzel AG, Brock JW, Bloom M, Newman RB, Kucklick JR, Cruze L, Somerville S, Wineland R, Butts C, Unal E (2017) Influence of race on prenatal phthalate exposure and anogenital measurements among boys and girls. Environ Int 110:61–70. https://doi.org/10.1016/j.envint.2017.10.007 CrossRefGoogle Scholar
- World Health Organization (2018) Arsenic—Fact Sheet. https://www.who.int/news-room/fact-sheets/detail/arsenic
- Yamamoto M, Kono N, Maurakami N, Yoshida T (1999) U.S. patent no. 5,863,303 Fuel oil consumption for diesel engines. Florham Park N.J.Google Scholar
- Zhang Z, Zhang H, Zhang J, Wang Q, Yang G (2018) Occurrence, distribution, and ecological risks of phthalate esters in the seawater and sediment of Changjiang River Estuary and its adjacent area. Sci Total Environ 619–620:93–102. https://doi.org/10.1016/j.scitotenv.2017.11.070 CrossRefGoogle Scholar