Dynamic Changes in DNA Damage and Repair Biomarkers with Employment Length among Nickel Smelting Workers

Our study explored the dynamic changes in andthe relationship between the DNA damage marker8-hydroxy-2＇-deoxyguanosine （8-OHdG） and theDNA repair marker 8-hydroxyguanine DNAglycosidase 1 （hOGG1） according to the length ofoccupational employment in nickel smeltingworkers. One hundred forty nickel-exposedsmelting workers and 140 age-matched unexposedoffice workers were selected from the Jinchangcohort. The 8-OHdG levels in smelting workers wassignificantly higher than in office workers （Z=-8.688,P〈0.05） and the 8-OHdG levels among nickelsmelting workers in the 10-14 y employment lengthcategory was significantly higher than among allpeers. The hOGG1 levels among smelting workerswere significantly lower than those of non-exposedworkers （Z=-8.948, P〈0.05）. There were significantdifferences between employment length andhOGG1 levels, with subjects employed in nickelsmelting for 10-14 y showing the highest levels ofhOGG1. Correlation analysis showed positivecorrelations between 8-OHdG and hOGG1 levels（r=0.413; P〈0.01）. DNA damage was increased withemployment length among nickel smelting workersand was related to the inhibition of hOGG1 repaircapacity.

Study on the synergy between intra-urban resident＇s migration and job change in Beijing

People＇s decisions of residential mobility in housing market and decisions of job change in labor market play an essential role in the formation and dynamics of urban spatial structure. This paper investigates the relationship between residential relocation and job change and its heterogeneity using a large-scale survey of residential living satisfaction and preferences in Beijing. Several conclusions are drawn as follows： 1） People＇s decisions of residential mobility are significantly positively correlated with their decisions of job change, indicating that these two-dimensional decisions are in fact a correlated decision process rather than two independent decision processes. 2） There is heterogeneity in the correlated decisions of residential mobility and job change. More specifically, the interrelationship between the decisions of residential mobility and job change among people without Beijing hukou, renters and single-worker households is more intensive than people with Beijing hukou, homeowners and multi-worker households. In addition, there is heterogeneity in the determinants of residential relocation and job change between groups with different types of housing tenure, household registration status and family employment structure. 3） For renters, commuting time can significantly increase the probability of residential relocation, which indicates that residents of different socioeconomic attributes have very different responses to commuting time costs.