| Lanzhou is an important industrial city in the northwestern region.It produces highly polluting petrochemical industry and also an important integrated transportation hub.It is one of the cities with relatively heavy environmental heavy metal pollution,which makes Lanzhou exposed to the potential threat of heavy metal exposure.At present,there are few reports on the comprehensive research on environmental air,drinking water,soil,and dust accumulation in Lanzhou.Therefore,the concentration of heavy metals in ambient air,drinking water,soil,and dust in Chengguan District of Lanzhou is known,and the exposure level of heavy metals in the crowd environment is quantified.The level of human health risks is of great significance to the further study of the exposure levels,contribution rates,health risks,and risk prevention of different environments,different pathways,and different media,as well as guidance for urban environmental governance and the construction of beautiful urban landscapes.Promoting the sustainable development of urban ecological environment has a positive effect.In the non-heating season,collecting ambient air,drinking water,soils and dusts,and using the microwave-ICP-MS to analyze the heavy metals concentration levels.Using Excel and SPSS software analyze the heavy metal content of each exposure route.Furthermore,the health risk assessment model recommended by US EPA was adopted to evaluate the health risks of heavy metal and multi-paths pollution levels in Chengguan district of Lanzhou city.The quality of the 10 kinds of heavy metal concentration in the air,according to the reference concentration of heavy metal elements in PM2.5,the family interior living place and office average mass concentration of heavy metals are not more than the limit;The outdoor space,The average mass concentration of As is higher than the limit 6 ng·m-3,other heavy metal concentration does not exceed the limit.The total non-carcinogenic hazard quotient of 10 kinds of heavy metals in individual breathing air particulates were 1.76.The non-carcinogenic hazard quotient of Mn is greater than 1 to 1.4,it is contribution rate was 79.57%.The non-carcinogenic hazard quotient of other nine heavy metals was less than 1.Five kinds of carcinogenic metals through breathing incremental lifetime cancer risk between 10-6~10-4,the total risk was 7.17×10-5.The total risk were relatively large and have long-term potential carcinogenic risk.The concentration of 10 heavy metals in drinking water in the survey area was consistent with the toxicological index of water quality standard and limit value in drinking water sanitation standard.The non-carcinogenic hazard quotient of 10 heavy metals in drinking water were less than 1.the total risk were 1.45.Four kinds of carcinogenic metals through drinking incremental lifetime cancer risk between 10-7 ~ 10-4,The total risk were 6.16×10-4.The incremental lifetime cancer risk of As was 6.16×10-4,contribution rate of 89.4%,should be taken seriously attention.Heavy metals in soils Mn,Ba,Cr,Ni,Pb and in dusts Ba,Pb,Cu,Zn,As,Cr,Cd,Co,Ni all higher than soil background value in Gansu province,affected by different degree of man-made pollution.The total non-carcinogenic hazard quotient of 10 heavy metals in soils and dusts was 1.49.The non-carcinogenic hazard quotient rates of As and Zn in the top two were respectively contributed 37.89% and 29.60%.Four kinds of carcinogenic metals through drinking incremental lifetime cancer risk between 10-7 ~ 10-3,the total risk were 1.18×10-3.The incremental lifetime cancer risk of As was 1.09×10-3,contribution rate of 92.15%,should be taken seriously attention. |
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