某癌症高发区水中多环芳烃测定及其风险评价

Detection and risk assessment of polycyclic aromatic hydrocarbons in underground and surface water of high cancer incidence area

在某癌症高发区选取5个镇中的10个村进行布点,分别在2010年6月和12月采集丰水期和枯水期水样,采用固相萃取与气相色谱-质谱联用方法对深层地下水、浅层地下水以及地表水中的多环芳烃(PAHs)进行测定.检测结果表明,深层地下水在丰、枯水期时PAHs总量分别为4058.29—9613.53 ng.L-1和72.78—809.00 ng.L-1.浅层地下水丰、枯水期PAHs总量分别为2205.84—24621.20 ng.L-1和82.88—601.95 ng.L-1.地表水丰、枯水期PAHs的总量分别为2747.44—33532.90 ng.L-1和127.78—321.04 ng.L-1.丰水期萘含量较高是造成PAHs总量在丰水期远高于枯水期的主要原因.10个水样中苯并(a)芘超标(GB5749—2006),最大超标8.42倍.采用优化的USEPA风险评价模型,对PAHs进行人体健康风险评价,其致癌风险水平在2×10-8—1.28×10-5之间,部分水样致癌风险超过10-6的水质监控值.

Fifty seven water samples from 10 villages of 5 towns in a high cancer incidence area were collected in June 2010（high flow period） and December 2010（low flow period）.The water samples from deep underground water,shallow groundwater and surface water were analyzed for 16 PAHs by SPE coupled with GC-MS.Concentrations of total PAHs in deep underground water during high and low flow period were respectively 4058.29 to 9613.53 ng · L-1 and 72.78 to 809.00 μg · L-1.Concentrations of total PAHs in shallow groundwater during high and low flow period were respectively 2205.84 to 24621.20 ng · L-1 and 82.88 to 601.95 ng · L-1.Concentrations of total PAHs during high and low flow period were respectively 2747.44 to 33532.90 ng · L-1 and 127.78 to 321.04 ng · L-1.The high concentration of naphthalene during high flow period resulted in high total PAHs during the period.Water samples during high flow period were collected during wheat harvest and transplanting rice seedlings.Thus,high concentration naphthalene from burnt stalks may have entered water bodies.Benzo（a）pyrene concentrations in ten samples exceeded the standard level（10 ng · L-1） and the maximal concentration of benzo（a）pyrene was 8.42 times higher than the Standard level（GB5749—2006）.The carcinogenic risk of PAHs was assessed using the improved USEPA model and the risk level was 2×10-8 to 1.28×10-5.So,the carcinogenic risk of some water samples exceeded the recommended risk index（10-6）.