The purpose of this study is to verify the structural relationship between job crafting and job enthusiasm, informal learning, social support, and positive psychological capital, and to investigate the effect of informal learning, social support, and positive psychological capital on job crafting through job enthusiasm. A survey was conducted on 451 safety workers at large domestic companies, and the collected data were analyzed for model suitability, influence relations between variables, and mediating effects with AMOS 23.0 using SPSS 23.0. Through research, we found five important results. First, the structural model of job crafting, job enthusiasm, informal learning, social support, and positive psychological capital properly explained the empirical data. Second, social support and positive psychological capital had a positive effect on job enthusiasm, but informal learning did not significantly affect job enthusiasm. Third, informal learning and positive psychological capital had a positive effect on job crafting, while social support did not significantly affect job crafting. Fourth, job enthusiasm had a positive effect on job crafting. Finally, job enthusiasm was found to mediate the relationship between social support and positive psychological capital and job crafting. These suggest that continuous environmental efforts and systematic management measures are needed to promote job crafting of safety workers so that informal learning, social support, positive psychological capital, and job enthusiasm can be expressed. Therefore, the necessity of developing various sub-factors of informal learning that can promote job crafting of safety workers was suggested as a follow-up study.

In order to explore the job crafting experience of millennial safety workers, this study conducted a qualitative case research with five safety workers of S Energy from March 26 to September 27, 2021 . As a result of the analysis, task crafting showed ‘matching one’s strong suit with a given task’, ‘expanding work knowledge using social network service (SNS)’, and ‘making changes in job performance methods for preemptive safety management activities’. Also, Cognitive crafting showed ‘recognition of social vocation as a safety job’, ‘recognition of a role to grow as a safety management expert’, and ‘cognitive changes from means of organizational adaptation to enjoyment and energy of life’. At the same time, in relation crafting, ‘establishment of amicable relationships through SNS in non-face-to-face and rapid communicating situations’, ‘safety management made through with mutual cooperations between business people’, and ‘reborn as a mutual safety net in business relationships’ appeared. These can be used as basic data to accumulate the theoretical basis for job crafting research of millennial safety workers and to improve their job satisfaction. A follow-up study was proposed for safety workers with occupations of various kinds.

This study was performed to provide the basic information on characteristics of groundwater pollution in Gyeongsan city. Forty two groundwater samples were collected, and pH, DO, COD, NH3-N, NO3--N, T-N, PO43--P, Cl, Ca, Mg, hardness, evaporate residues and others were investigated. And, ANOVA analyses were carried out to reveal the differences in water pollution indicator values of by industry, commerce/residence and agriculture areas. The results were as follows. 1. The mean values of pH, DO, COD, NH3-N, NO3--N, T-N, PO43--P, Cl, evaporate residues, Ca and hardness were 6.9, 7.9 ㎎/ℓ, 0.4 ㎎/ℓ, 2.44 ㎎/ℓ, 2.73 ㎎/ℓ, 6.06 ㎎/ℓ, 0.82 ㎎/ℓ, 32.72 ㎎/ℓ, 381.67 ㎎/ℓ, 41.53 ㎎/ℓ, 177.17 ㎎/ℓ, respectively. 2. As groundwater became deeper, the values of Cl, Ca, Mg, Na, hardness and evaporate residues remarkably increased, but those of COD, NH3-N, NO3--N, NO2--N, T-N decreased. 3. The values of COD, Cl, Ca, Mg, Na, hardness and evaporate residues were very high in industrial area, and those of NH3-N, NO2--N, T-N were very high in commercial/residential area, and those of NO3--N were a little high in agricultural area. 4. The correlations between depth and each value of Mg, Na, Fe, hardness and evaporate residues were highly positive, and those between DO and each value of Mg, Cu, Fe, hardness and evaporate residues were highly negative. 5. According to ANOVA analyses, the differences in three area groups (industry, commerce/residence and agriculture) on the values of NH3-N, T-N, evaporate residues, hardness, Ca, Mg, K and Fe were significant at 1% level.