Monitoring and Risk assessment of Brominated Flame Retardants and Phthalate esters from House Dust in South-Korea

Abstract

Brominated flame retardants (BFRs), such as polybrominated diphenyl ethers (PBDEs), tetrabromobisphenol-A (TBBPA), and hexabromocyclododecane (HBCD), have been increasingly produced and consumed throughout the world during the past decade due to their relatively low cost and higher fire-resistant efficiency. This increase has been accompanied by growing public concern about the risk to humans and the environment. In fact, several BFRs have been globally restricted as hazardous substances. Phthalates have also been used as plasticizers in numerous plastic products, such as construction materials and household goods. Similar to BFRs, phthalates are relatively inexpensive yet efficient and their production and consumption has increased dramatically worldwide over the past decade, along with public concern about the risk to humans. BFRs and phthalate esters have been known as endocrine disrupter mimicking hormonal functions. There have been many studies about these materials in foreign countries, but there is a lack of such research in South Korea. In this research, we therefore studied BFRs and phthalates, their distribution based on building characteristics, and their associated health risks. In particular, we investigated the health risk posed by house dust containing these materials. We also reviewed foreign studies and conduct a comparative analysis. In this study, we found the concentration levels of ΣPBDEs to be much lower than in the US and the UK but almost the same as in Australia and China. This is likely because these substances have accumulated more in advanced countries than in developing countries, as they have been used in household applications there for longer periods of time before being regulated. We also found the concentrations of ΣHBCD and TBBPA to be lower than those reported in some advanced countries. This indicated that these materials started to be used as alternatives to PBDEs earlier in advanced countries, before regulations were instituted. In addition, the levels of phthalate esters in Europe and the US were lower than those in Asia. This might indicate the more frequent use of products containing phthalates, such as PVC flooring, in Asian countries. We implemented a distribution impact study of building characteristics, such as flooring type (PVC) and construction age. PVC flooring was associated with DEHP (p=0.001) and BBP (p=0.012), and construction age was statistically correlated with BDE-47 (p=0.062), BDE-203 (p=0.007), DEHP (p=0.004), and BBP (p=0.070). These results are evidence that older buildings have more materials containing PBDEs and phthalates

thus, the more PVC used, the higher the exposure to phthalates. We also carried out a health risk assessment of PBDEs and phthalates in terms of these materials being carcinogenic or non-carcinogenic. Only DEHP (ECR=1.4×10-6) in target compounds was found to have a carcinogenic risk. It reached the criterion of 10-4 to 10-6, according to a carcinogenic health effect index established by the US Environmental Protection Agency (USEPA). We concluded that DEHP levels in indoor dust need to be continuously monitored.