| Polycyclic aromatic hydrocarbons (PAHs) are organic toxicants and ubiquitously present in the environment. Human exposure to PAHs may occur through ingestion, inhalation and dermal contact and lead to higher cancer incidence such as lung, shin and bladder. The economic growing in Guangdong province has made the environmental deterioration. The research indicated that the PAH level in PM2 5 in Guangzhou is high now and may influence the health of local inhabitants. There are many researches about the urinary monohydroxy PAH metabolites in the world. But in our country, the study in this area is just preliminary.The main biomarker often used in our country is 1-hydroxypyrene. And as the health risk assessment of human exposure to PAHs is deduced by amibient monitoring it is difficult to evaluate the exposure level of an individual person objectively.In this thesis, an analytical method-LC-MS/MS was developed using 11 urinary metabolites as the biomarkers. The objects in our study consisted of the middle school students in Guangzhou, Conghua and Zhuhai in Pearl River Delta, the workers in an electronic waste recycling site-Guiyu and the control groups near the areas of Guiyu. The non-occupational human exposure and occupational exposure level to PAHs in some areas of Guangdong was reported and some environmental factors which may influence the exposure level were discussed.First, two analytical methods about LC-MS/MS were developed to determine the PAH metabolites in urine. 1-hydroxypyrene and 3-hydroxybenzo (a) pyrene can be separated in positive atmospheric pressure chemical ionization (APCI) mode within only 10 min. It is suitable for the fast determination of large number of urinary samples. At the same time, under the negative electrospray ionization (ESI) mode, another method with higher sensitivity was set up. More metabolites in urine can be detected by this method, including 1 -, 2-hydroxynathalene, 2-hydroxyfluorene, 1 -, 2-, 3-, 9-, 4-hydroxyphenanthrene, 1-hydroxypyrene, 6-hydroxychrysene and 3-hydroxybenzo (a) pyrene. The limits of detection are low (0.04-0.61μg/L) and it was basic for the biominitoreing of human PAH exposure.The study on the the non-occupational exposure to PAH for students in Conghua, Zhuhai and Guangzhou revealed that 9 urianry PAH metabolites with two to four rings were detected in the all. The midian and range (μmol/mol creatinine) in the three cities were 2.67 (0.08-13.93), 1.42 (0.10-4.73) and 3.49 (0.70-86.65) for 2-hydroxynapthalene, 0.85 (0.15-11.12), 0.41 (0.00-2.74) and 1.69 (0.56-79.84) for 1-hydroxynapthalene, 1.04 (0.10-6.26), 0.71 (0.08-3.10) and 1.54 (0.40-6.40) for 2-hydroxyflurene, 0.12 (0.05-0.92), 0.07 (0.01-0.33) and 0.18 (0.06-1.06) for 2-hydroxyphenanthrene, 0.18 (0.07-0.74), 0.11 (0.02-1.06) and 0.25 (0.05-0.50) for 3-hydroxyphenanthrene, 0.21 (0.06-2.90), 0.20 (0.06-1.14) and 0.64 (0.19-1.53) for 1-+9-hydroxyphenanthrene, 0.03 (0.00-0.22), 0.004 (0.00-0.24) and 0.008 (0.002-0.14) for 4-hydroxyphenanthrene, 0.82 (0.20-3.72), 0.42 (0.00-1.85) and 1.42 (0.23-6.98) for 1-hydroxypyrene, respectively. Compared with students' exposure level to PAHs in Conghua and Zhuhai, the students in Guangzhou were higher. As the students' habits in the three cities were same, the environmental factor may be the main reason which leads to the siginificant difference. And compared with the exposure level in Occident, the levels in Guangzhou were also distinctly higher. For example, the PAH metabolite concentrations of students in Guangzhou were about as 10 time as the background groups in the same age in USA.The study about the worker occupational exposure to PAHs in Guiyu and the control groups living in the near areas of Guiyu indicated that the urinary PAH metabolite midian and range (μmol/mol creatinine) values for the workers in the three exposure sites were 6.76 (1.07-34.69), 9.90 (1.72-33.91) and 13.01 (1.75-32.46) for 2-hydroxynapthalene, 2.03 (0.33-8.91), 3.43 (0.48-21.01) and 2.89 (0.19-24.44) for 1-hydroxynapthalene, 5.91 (0.30-20.46), 4.46 (0.52-10.79) and 4.77 (0.40-15.24) for 2-hydroxyflurene, 0.22 (0.03-0.76), 0.19 (0.07-0.40) and 0.17 (0.05-0.71) for 2-hydroxyphenanthrene, 0.25 (0.06-0.66), 0.27 (0.11-0.79) and 0.31 (0.06-1.13) for 3-hydroxyphenanthrene, 0.69 (0.10-2.53), 0.61 (0.20-1.69) and 0.55 (0.21-1.98) for 1-+9-hydroxyphenanthrene, 0.02 (0.00-0.37), 0.03 (0.00-0.10) and 0.03 (0.00-0.19) for 4-hydroxyphenanthrene and 0.73 (0.20-4.00), 0.48 (0.00-1.42) and 0.93 (0.04-10.17) for 1-hydroxypyrene, respectively. It was comparable to the reports of kinds of occupational exposure level. But the levels for the control groups in the near areas of Guiyu were significantly different from other background groups reported. It indicated that the population produced by open waste recycling mode in Guiyu had influenced the health of local residents.All the correlation studies indicated that there were good correlation coefficients between 2-hydroxynathalene and the sum of hydroxynathalene, 1-+9-hydroxyphenanthrene and the sum of hydroxyphenanthrene, 2-hydroxyfluorene and other metabolites, respectively. But the correlation coefficients among 1-hydroxypyrene and other metabolites were not so good. So only use 1 -hydroxypyrene as the biomarker to monitor the PAH exposure level will lead to the individual difference, it is necessary to monitor with more hydroxy metabolites as the common biomarkers. The analysis results showed that using 2-hydroxynathalene, 1-+9-hydroxyphenanthrene, 2-hydroxyfluorene and 1-hydroxypyrene as the biomarker were more suitable. Moreover, the ratios of 2-hydroxynathalene and 1 -hydroxynathalene and the ratios of mono-hydroxyphenanthrene within the sum of hydroxyphenanthrene were different with the other researchs reported. The reason need to be studied in the further.In a word, LC-ESI (-) -MS/MS is a sensitive and reliable method for the biomonitoring of urinary PAHs metabolites by multiple biomarkers. PAHs in the atmosphere in Guangzhou and Guiyu are the main exposure source for the population. The waste water and gases released by the electronic waste recycling mode have deeply influenced the health of local inhabitants.
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