| As a kind of brominated alicyclic additive flame retardant?BFRs?,hexabromocyclododecanes?HBCDs?have been of great concern due to their persistance,bioaccumulation,high lipophilicity and long distance migration.HBCDs which are the major production of additive-type flame retardants are widely used in home,office,vehicle interior and other indoor environment.Human beings in the indoor environment for more than 80%,studies have shown that indoor dust intake has become an important way of human exposured to BFRs,gradually by the environmental scientists attention.As China's largest city,Shanghai is the economic,transportation,industrial center.With the continuous increasing in the number of population,the pollution of BFRs indoor environment have gradually increased.At present,studies have shown BFRs are common in environmental media in Shanghai.However,the researchs on HBCDs in indoor environment are less,especially for the content which the distribution and exposure of HBCDs in indoor dust in Shanghai.In this research,the concentration level,composition and source of HBCDs in Shanghai indoor dust were systematically studied by liquid chromatography-tandem mass spectrometry?LC-MS/MS?.The effect of particle size on the concentration of HBCDs in dust was investigated and the human exposure level of HBCDs in indoor dust was evaluated for the first time in Shanghai.This study will provide theoretical data and technical support for related research.The main results of this study are as follows:?1?The detection rate of HBCDs in indoor dust samples?n=40?in Shanghai was 97.5%.The concentration range of?HBCD in indoor dust is between nd and 72.39 ng·g-1,the average concentration was 18.24 ng·g-1 and the intermediate concentration was 11.75 ng·g-1.The concentration of?HBCD in the dust after 100 mesh sieve was between nd and 70.33 ng·g-1,the average concentration was 21.54 ng·g-1 and the median concentration was 15.90 ng·g-1.The concentration of?HBCD in the dust after 200 mesh sieve was between1.772-72.39 ng·g-1,the average concentration was 21.48 ng·g-1 and the median concentration was 17.33 ng·g-1.In general,compared with Europe,the United States,Oceania,Asia and other regions,the concentration level of HBCDs in indoor dust in Shanghai is low,this is consistent with the use of flame retardants in different areas.?2?For 100 mesh and 200 mesh particles of indoor dust,the concentration trend is such that the concentration of HBCDs in 100 mesh is less than 200 mesh as a whole.This may be possible that the smaller the particles,the more the number of particles under the same mass of dust samples?0.3 g?.This results in a larger specific surface area,which can adsorb more HBCDs.?3?The relative percentages of?-HBCD,?-HBCD and?-HBCD in indoor dust samples in Shanghai were 20.9%-100%?average 76.5%?,0.0%-17.0%?average 7.5%?,0.0%-69.8%?average 24.4%?.In this study,we found that isomers were mainly?-HBCD.But in this study there is a certain degree of difference among Europe and the United States and other regions,?-HBCD is the main isomer in some areas.It may be due to its different supplies,the global greenhouse effect and light pollution,leading to the probability of mutual transformation between isomers.In this study,?-HBCD is the main isomer,so it is worthwhile to assess its accumulation and harm to organisms.?4?Spearman correlation analysis showed that there is a significant and positive correlated between all three diastereoisomers and?HBCD in indoor dust from Shanghai,which indicates that they have similar sources of contamination.?5?Compared with the exposure of HBCDs at home and abroad,this study found that the exposure in Shanghai is low.For toddlers?12-24 months?and adults,the ingestion intake,dermal intake and inhalation intake were 0.0905 and0.0295 ng·kg-1·d-1,0.0008 and 0.0001 ng·kg-1·d-1,2.55E-07 and 1.04E-07ng·kg-1·d-1,respectively.Which maybe due to the recent prohibition of the addition of HBCDs.At the same time we also found that childhood stage is the main period that exposed to HBCDs by indoor dust.It's related to the child's crawling and the contact beteen the hand and the mouth.Non-food intake is the main route of exposure to HBCDs in indoor dust,skin intake as a secondary route. |
PDF Full Text Request