<span>The financial performance of a bank can be measured through ROA. Bank Indonesia as a supervisory and supervisory institution prioritizes greater profitability, namely the Return on Asset (ROA) of a bank, so banks need to know what factors can affect the ROA of a bank. This study was conducted to analyze the effect of Non Performing Loans (NPL) and Loan to Deposit Ratio (LDR) on Return on Assets (ROA) with Net Interest Margin (NIM) as a mediating variable. The sample of this research consists of Bank Mandiri, Bank BNI, Bank BRI, and Bank BTN for the period 2015-2019. The research methods used include descriptive statistical analysis, outer model analysis, and inner model analysis. The results of this study indicate that NPL does not affect NIM, while LDR has a significant effect on NIM. Furthermore, NPL has a significant effect on ROA, while LDR does not affect ROA. This study also proves that NIM has a significant effect on ROA, but NIM does not mediate the effect of NPL on ROA, and NIM can mediate the effect of </span><span>LDR on ROA.</span>

Human hair can absorb elements that enter the body through food/digestion, respiration and skin. The presence and concentration of an element in the hair can reflect the state/health status in which a person lives and works. The sulfhydryl and disulfide groups in hair are able to bind trace elements that enter the body and then are bound in the hair.  This study aims to determine the levels of Lead (Pb) in the hair of motorcycle workshop workers (mechanics) in the city of Padang.  The type of research used in this study is a descriptive survey, which is to describe the levels of Lead (Pb) in the hair of motorcycle mechanical in Padang City. Laboratory examination using Atomic Absorption Spectrophotometry (AAS) method to determine quantitatively lead (Pb) levels using are 10 samples. Based on result show that there are 8 respondents who were positively exposed to lead (Pb) but still in normal levels. And the highest lead (Pb) value was in hair sample 6, which was 0.9404 mg/kg. The benefits of this research are input and information about the dangers of lead pollution which can harm health.