福州市道路灰尘中多环芳烃粒径分布、生物可利用度及其毒性当量

Distribution,bioaccessability and toxicity equivalence of polycyclic aromatic hydrocarbons in different particle-size fractions of road dust in Fuzhou

以福州道路灰尘为研究对象,研究了不同粒径灰尘(>250μm、250—53μm和<53μm)中多环芳烃(PAHs)的含量和组成,并利用体外消化模型结合固相萃取技术评估了不同粒径灰尘中PAHs的生物可利用度以及有效态PAHs的苯并(a)芘(BaP)毒性当量浓度(TEQBaP).结果表明,(1)不同粒径灰尘中PAHs总量随粒径减小而增加(>250μm,0.597 mg·kg^(-1);250—53μm,1.235 mg·kg^(-1);<53μm,3.931 mg·kg^(-1)).不同粒径灰尘中PAHs组成基本相同,都为4环(58.5%±0.8%)>5环(21.5%±0.4%)>3环(13.3%±0.9%)>6环(4.8%±0.2%)>2环(2.0%±0.3%);(2)不同粒径灰尘中有效态PAHs总量随粒径减小而增加,但>250μm粒径灰尘中PAHs的生物可利用度显著高于250—53μm和<53μm粒径灰尘(P<0.05).总体上,低环(2环、3环和4环)PAHs生物可利用度要大于高环(5环和6环)PAHs;(3)不同粒径灰尘中有效态PAHs的总TEQBaP值随粒径减小而增大,且不同粒径灰尘中4环和5环PAHs的TEQBaP值都显著高于其他环数PAHs(P<0.05).由于不同粒径灰尘中4环PAHs含量都最高,且其具有较高的生物可利用度和TEQBaP值,因而在人体内潜在毒性风险最高.

The content and composition of polycyclic aromatic hydrocarbons(PAHs)in different particle-size fractions(>250μm,250—53μm and<53μm)of the road dust from Fuzhou city were studied.Moreover,the bioaccessability of PAHs and the toxic equivalent concentration based on the toxicity of benzo(a)pyrene(BaP)(TEQBaP)of the bioavailable PAHs in different particle-size fractions of the dust were evaluated by an in vitro digestion model combined with solid phase extraction technique.The results showed that:(1)the total contents of PAHs in different particle-size fractions of the dust increased with the decrease of particle size(>250μm,0.597 mg·kg^(-1);250-53μm,1.235 mg·kg^(-1);<53μm,3.931 mg·kg^(-1)).The compositions of PAHs in different particle-size fractions of the dust were basically the same,all of which were in the sequence of 4-ring(58.5%±0.8%)>5-ring(21.5%±0.4%)>3-ring(13.3%±0.9%)>6-ring(4.8%±0.2%)>2-ring(2.0%±0.3%);(2)The total contents of the bioavailable PAHs in different particle-size fractions of the dust increased with the decrease of particle size,but the bioaccessability of PAHs was significantly higher in the>250μm dust than in the 250-53μm and<53μm dust(P<0.05).Overall,the bioaccessability of low-ring(2-,3-,and 4-ring)PAHs was greater than that of high-ring(5-,6-ring)PAHs;(3)The total TEQBaP value of the bioavailable PAHs in different particle-size fractions of the dust increased with the decrease of particle size,and the TEQBaP values of 4-ring and 5-ring PAHs in different particle-size fractions of the dust were significantly higher than those of other ring number PAHs(P<0.05).The 4-ring PAH content was the highest in different particle-size fractions of the dust and they also had high bioaccessability and TEQBaP values,thus their potentially toxic risk in human was the highest.