Abstract: A wide range of persistent and toxic chemicals is generated through the use of various consumer products: pharmaceuticals and personal care products (PCPPs), detergents, disinfectants, plasticizers, preservatives, microplastics, and nanomaterials, etc. [1,2]. These chemicals and their metabolites can be found in different environmental media, including wastewater, agricultural and urban runoff, lakes, rivers, ground water and drinking water. The conventional wastewater and (drinking) water treatment processes are not always efficient in removing them [3-6]. Some of these potent chemicals may enter the food chain, posing health threats, mainly through consumption of contaminated seafood [7]. The major objectives of this presentation are to review the current status on the sources, fates and health effects of some major emerging chemicals of concern, with emphasis on phthalates [8,9], bisphenol A [10], perfluorooctane sulfonate (PFOS) [11], and PCPPs [12], citing some local examples in South China (including Hong Kong). It is also intended to review the exposure pathways of these chemicals, and their potential associations with body loadings and associated health effects. It is known that autism spectrum disorders in children is related to exposure to various environmental pollutants [13]. These endocrine disrupting chemicals such as bisphenol A and phthalates are widely detected in indoor dust [14,15], food items such as fish [16-19] and meat [20], and blood plasma of local residents [21]. Nevertheless, there seems to be an urgent need to study the potential toxic effects of microplastics (particle size smaller than 5 mm), including those derived from PCPPs, as they are now widely distributed in the coastal environment, and their uptake mechanisms by fish, and the long-term health impacts on consumers are largely unknown. It seems essential to manage these emerging chemicals of concern more effectively, both nationally and internationally [1].

Key words: phthalates, bisphenol A, microplastics, exposure pathways, toxicity.

References
[1] Wong MH, Armour MA, Naidu R, Man M (2012). Persistent toxic substances: sources, fates and effects. Rev Environ Health 27: 207-13.
[2] Bouwman H, Wong MH, Barra R (2012). GEF Guidance on Emerging Chemicals Management Issues in Developing Countries and Countries with Economy in Transition. UNEP/GEF.
[3] Man M, Wong MH (2012) Removal of persistent organic pollutants (POPs) and compounds of emerging concern (CECs) in public owned sewage treatment works (POSTW) – a review. In: Environmental Contamination – Health Risks and Ecological Restoration. Wong MH (Ed) Taylor and Francis/CRC, London.
[4] Man YB, Chow KL, Man M, Lam JCW, Lau FTK, Fung WC, Wong MH (2015). Profiles and removal efficiency of polybrominated diphenyl ethers by two different types of sewage treatment work in Hong Kong. Sci Total Environ 505: 261-68.
[5] Chow KL, Man YB, Tam NFY, Liang Y, Wong MH (2017). Removal of decabromodiphenyl ether (BDE-209) using a combined system involving TiO 2 photocatalysis and wetland plants. J Hazard Mater 322: 263-9.
[6] Man, YB, Chow KL, Tsang YF, Lau FTK, Fung WC, Wong, MH, (2018). Fate of bisphenol A, perfluorooctanoic acid and perfluorooctanesulfonate in two different types of sewage treatment works in Hong Kong. Chemosphere, 190: 358-367.
[7] Wong MH (2017). Chemical pollution and seafood safety, with a focus on mercury: The case of Pearl River Delta, South China. Environ Technol Innov 7:63-76.
[8] Lü H, Mo CH, Zhao HM, Xiang L, Katsoyiannis A, Li YW, Cai QY, Wong MH (2018). Soil contamination and sources of phthalates and its health risk in China: A review. Environ Res 164: 417-29.
[9] Wang W, Leung AOW, Chu LH, Wong MH (2018). Phthalates contamination in China: Status, trends and human exposure – with emphasis on oral intake. Environ Pollut 238: 771-782.
[10] Huang YQ, Wong CKC, Zheng JS, Bouwman H, Barra R, Wahlstrom B, Neretin L, Wong MH (2012). Bisphenol A (BPA) in China: A review of sources, environmental levels, and potential human health impacts. Environ Int 42: 91-9.
[11] Zhao YG, Wong CKC, Wong MH (2012). Environmental contamination, human exposure and body loadings of perfluorooctane sulfonate (PFOS), focusing on Asian countries. Chemosphere 89: 355-68.
[12] Liu JL, Wong MH (2013). Pharmaceuticals and personal care products (PPCPs): A review on environmental contamination in China. Environ Int 59: 208-24.
[13] Ye BS, Leung AOW, Wong MH (2017). The association of environmental toxicants and autism spectrum disorders in children. Environ Pollut 227: 234-42.
[14] Kang Y, Man YB, Cheung KC, Wong MH (2012). Risk assessment of human exposure to bioaccessible phthalate esters via indoor dust around the Pearl River Delta. Environ Sci Technol 46: 8422-30
[15] Wang W, Wu FY, Huang MJ, Kang Y, Cheung KC, Wong MH (2013). Size fraction effect on phthalate esters accumulation, bioaccessibility and in vitro cytotoxicity of indoor/outdoor dust, and risk assessment of human exposure. J Hazard Mater 261: 753-62.
[16] Cheng Z, Nie XP, Wang HS, Wong MH (2013). Risk assessments of human exposure to bioaccessible phthalate esters through market fish consumption. Environ Int 57-58: 75-80.
[17] Cheng Z, Li HH, Wang HS, Zhu XM, Sthiannopkao S, Kim KW, Yasin MSM, Hashim JH, Wong MH (2016). Dietary exposure and human risk assessment of phthalate esters based on total diet study in Cambodia. Environ Res 150: 423-30.
[18] Wei X, Huang YQ, Wong MH, Giesy JP, Wong CKC (2011). Assessment of risk to humans of bisphenol A in marine and freshwater fish from Pearl River Delta, China. Chemosphere 85:122-8.
[19] Zhao YG, Wan HT, Law AYS, Wei X, Huang YQ, Giesy J, Wong MH, Wong CKC (2011). Risk assessment for human consumption of perfluorinated compound-contaminated freshwater and marine fish from Hong Kong and Xiamen. Chemosphere 85: 277-83.
[20] Law AYS, Wei X, Zhang XW, Mak NK, Cheung KC, Wong MH, Giesy J, Wong CKC (2011). Biological analysis of endocrine-disrupting chemicals in animal meats from the Pearl River Delta, China. J Expo Sci Environ Epidemiol 22: 93-100.
[21] Wan HT, Leung PY, Zhao YG, Wei X, Wong MH, Wong CKC (2013). Blood plasma concentrations of endocrine disrupting chemicals in Hong Kong populations. J Hazard Mater 261: 763-9.

Biography: Prof. Wong is currently Advisor and Research Chair Professor of Environmental Science, The Education University of Hong Kong, and Distinguished Visiting Professor of School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, China. His research areas included environmental and health risk assessments of persistent toxic substances, ecological restoration of contaminated sites, and recycling of organic wastes, with a focus on upgrading food wastes as fish feeds. He has published over 690 SCI papers and 32 book chapters, edited 25 books/special issues of scientific journals, and has successfully filed 5 patents. A recent exercise assessing papers published 1996-2018, based on Scopus: citation, H-index, Hm-index, etc.; Prof. Wong ranked 24, and the most cited Chinese scientist worldwide, under Environmental Science (Sept., 2019).

Prof. Wong served as the Coordinator of Central and North-East Asia of the project “Regionally based assessment of Persistent Toxic Substances”, and as a Panel Member (of three experts) of another project “Chemicals Management Issues of developing countries and countries with economies in transition”, both sponsored by UNEP/GEF, during 2001-2003, and 2010-2012, respectively.