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.

City size and employment dynamics in China:Evidence from recruitment website data

This article explored China’s urban employment dynamics with particular focus on the city size effect.Big data derived from the largest recruitment website were used to examine the direct and indirect impacts of city size on employment demand by using mediating and moderating models.We also investigated the roles of the government and location factors which have seldom been considered in literature.Results showed that the concentration degree of new jobs is higher than that of stock employment and population across cities,implying a path dependency mechanism of job creation and employment expansion.Meanwhile,numerous job posts in inland central cities are probably a symptom of more even distribution of employment in future China.Econometric models further verified the significant correlation between city size and job creation.Moreover,industrial diversity,fixed asset investment,and spatial location have heterogeneous effects on employment demand in cities of different sizes and different levels of administration.These results can not only deepen our understanding of the crucial role of city size in urban employment growth but also demonstrate the future trend of labor and population geography of China.Policy implications are then proposed for job creation in cities of China and other developing countries.