Multiple Exposure Pathways And Health Risk Assessment Of Heavy Metal(loid)s For Children Living In A Fourth-tier City In Hubei Province

Objective: Previous studies have focused on the health risks of children and adults exposed to heavy metals in typical contaminated areas,suggesting that diet is the main way for people to be exposed to heavy metals.Residents living in fourth-tier cities are faced with the dual impact of modern logistics supply and local extensive production industry,and their lifestyles have undergone great changes.The level of local children’s exposure to heavy metal(loid)s and their health risks deserve our attention.Methods: This study carried out researches on the multipath heavy metal(loid)s exposure and health risk assessment for children aged 3-4 years in kindergarten and 10-13 years in primary school.Based on the children’s questionnaire information,soil,dust,atmospheric particulate matter,drinking water,daily diet and children’s 24-hour urine samples were collected from kindergarten,schools and their families.To further assess dietary exposure,this study simultaneously collected multiple food samples from the local markets.Inductively coupled plasma mass spectrometer(ICP-MS)was used to determine the concentrations of lead(Pb),chromium(Cr),manganese(Mn),cobalt(Co),nickel(Ni),copper(Cu),zinc(Zn),cadmium(Cd),vanadium(V),arsenic(As),mercury(Hg)and antimony(Sb)in various environment and urine samples,to assess the health risks of children exposed to heavy metal(loid)s.Results: The results showed that the concentrations of Cd in the soil and dust samples and the concentrations of Mn in the atmospheric particulate samples were relatively high,and the Pb,Cd and Mn levels in the urine samples were higher than those in the residents of Wuhan city and some typical polluted area,indicating a serious environmental pollution.Then,the study found that almost no crops were grown locally,and most of the living foods came from planting bases in other provinces,and the metal contents in the foods were very low,while atmospheric particles became the main way for local children to be exposed to heavy metal(loid)s.The health risk assessment results showed that the Hazard Index(HI)of Mn was greater than 1,and the main non-carcinogenic risk still came from atmospheric particulate exposure.In addition,the Incremental Lifetime Cancer Risk(ILCR)for the five metal(loid)s(Cr,Co,Ni,Cd,As)at the median concentration was lower than the maximum acceptable level,but the total ILCR value of all metals at the 95 th percentile was significantly higher than the threshold,suggesting that the potential carcinogenic risk of heavy metal(loid)s for local children needed sufficient attention.Conclusions: This study explored the true level of heavy metal(loid)s exposure of children living in a fourth-tier city,and confirmed that atmospheric particles had become the main way for local children to be exposed to heavy metal(loid)s.The non-carcinogenic risk of Mn was high,and the total ILCR of all metals at the 95 th percentile was still worthy of attention.This study provides a scientific basis for protecting the health of children in fourth-tier cities and adopting corresponding prevention and control strategies.