Biomonitoring of organophosphate triesters and diesters in human blood in Jiangsu Province, eastern China: Occurrences, associations, and suspect screening of novel metabolites

Miaolei Ya; Nanyang Yu; Yayun Zhang; Huijun Su; Song Tang; Guanyong Su

doi:10.1016/j.envint.2019.105056

Biomonitoring of organophosphate triesters and diesters in human blood in Jiangsu Province, eastern China: Occurrences, associations, and suspect screening of novel metabolites

Environ Int. 2019 Oct:131:105056. doi: 10.1016/j.envint.2019.105056. Epub 2019 Jul 29.

Authors

Miaolei Ya¹, Nanyang Yu², Yayun Zhang¹, Huijun Su¹, Song Tang³, Guanyong Su⁴

Affiliations

¹ School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu, China.
² State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China.
³ National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing 100021, China; Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, Jiangsu 211166, China.
⁴ School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu, China. Electronic address: sugy@njust.edu.cn.

PMID: 31369981
DOI: 10.1016/j.envint.2019.105056

Abstract

Since organophosphate (OP) triesters are ubiquitous in environmental matrices, there is an increasing concern regarding human exposure to OP triesters or their metabolites. In this study, we measured levels of 16 OP triesters and 4 OP diesters in n = 99 human blood samples of non-occupationally exposed adults (aged 18-87) from Jiangsu Province, eastern China. Based on the measured concentrations, statistical difference and correlativity were calculated to characterize the population diversity and potential sources of OP triester and diester. Di (2-ethylhexyl) phosphate (DEHP) and 2-ethylhexyl diphenyl phosphate (EHDPP) were found in many participants' blood, with median concentrations of 1.2 (range: n.d. - 44.7, detection frequency: 99%) and 0.85 (n.d. - 28.8, 68%) ng mL^-¹, respectively. Blood samples of older participants contained significantly lower concentrations of OP diesters or triesters than their younger counterparts (p < 0.01). Regional- and age-specific differences in the blood concentrations of OP triesters and diesters were attributed to disparities in environmental exposure intensity. EHDPP and tris (phenyl) phosphate (TPHP), the predominant OP triesters, exhibited significant positive correlation (p < 0.01, r = 0.84) suggestive of analogous transport behavior from similar exposure sources to humans. The increased correlations between diphenyl phosphate (DPHP) and TPHP as well as with EHDPP as observed from the multivariate regression suggests that DPHP could be derived from the metabolism of both TPHP (the crucial precursor) and EHDPP. When the blood samples were subsequently screened using high-resolution spectrometry, we detected five novel OP metabolites: glucuronide conjugates of hydroxylated DEHP (OH-DEHP glucuronide conjugate), 2-ethylhexyl monophenyl phosphate (EHMPP), hydroxylated EHMPP (OH-EHMPP), dihydroxylated bis(2-butoxyethyl) phosphate (di-OH-BBOEP), and dihydroxylated tris(butyl) phosphate (di-OH-TNBP). Overall, this study provides novel information regarding the occurrence of OP triesters and diesters, and further suggested several novel OP metabolites in human blood.

Keywords: DEHP; EHDPP; Human blood; OP diesters; OP triesters; Suspect screening.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adolescent
Adult
Aged
Aged, 80 and over
Biological Monitoring*
China
Environmental Exposure* / analysis
Environmental Exposure* / statistics & numerical data
Humans
Middle Aged
Organophosphates / blood*
Young Adult

Substances

Organophosphates