Association between Socio Economic Status and Blood Cadmium in Korea

• Published in: Epidemiology and health 2019-05, p.e2019018
• Main Authors: Jee, Yongho, Cho, Sung-Il
• Format: Article
• Language: English
• ISSN: 2092-7193

Although smoking is associated with a low socio-economic status (SES) as well as blood cadmium level, the association between SES and cadmium level is not clear. Therefore, our study aimed to examine the association and clarify whether role of smoking as the confounding or mediator. Data (n=7,734) were the Korea National Health and Nutrition Examination Survey (KNHANES, 2008-2011) and involved years that were containing blood cadmium and cotinine data. We investigated the association of income, education, and occupation with blood cadmium level. Smoking variable was investigated by categorizing smoking status (never, former and current), pack-year into quartile variables. Regarding dietary factor, intake of rice and barely was analyzed by frequency of rice and barely intake per week. Additionally, urinary cotinine level was used to guarantee the validity of smoking variables. Participants earning low income and less education had higher blood cadmium levels. After controlling for smoking, the association between income and cadmium level became substantial decrease. Further controlling for education, the associations between income and cadmium level were disappeared. However, there was strong negative association between education and cadmium level even after controlling for smoking history, pack-year, and urinary cotinine. In cross sectional data from KNHANES, blood cadmium levels were significantly higher among those with low income and less education levels. These associations were contributed by smoking history, but still remained.