Worker Safety in the Rare Earth Elements Recycling Process From the Review of Toxicity and Issues

Although the rare earth elements (REEs) recycling industry is expected to increase worldwide in high-tech industry, regulations for worker safety have yet to be established. This study was conducted to understand the potential hazard/risk of REE recycling and to support the establishment of regulations or standards. We review the extensive literature on the toxicology, occupational safety, and health issues, and epidemiological surveys related to the REEs, and propose suitable management measures. REE recycling has four key steps such as collection, dismantling, separation, and processing. In these processes, hazardous substances, such as REEs-containing dust, metals, and chemicals, were used or occurred, including the risk of ignition and explosion, and the workers can be easily exposed to them. In addition, skin irritation and toxicities for respiratory, nervous, and cardiovascular systems with the liver toxicity were reported; however, more supplementary data are needed, owing to incompleteness. Therefore, monitoring systems concerning health, environmental impacts, and safety need to be established, based on additional research studies. It is also necessary to develop innovative and environment-friendly recycling technologies, analytical methods, and biomarkers with government support. Through these efforts, the occupational safety and health status will be improved, along with the establishment of advanced REE recycling industry.

A 6-Week Oral Toxicity Study of Oral Cholera Vaccine in Sprague-Dawley Rats

The present study was carried out to examine the toxicity and target organs of oral cholera vaccine (OCV) after repeated oral administration in Sprague-Dawley rats for 6 weeks (3 administrations, once every 2 weeks). OCV is an inactivated oral cholera vaccine that contains Vibrio cholerae and confers protection against cholera caused by V. cholera serogroups O1 (Inaba and Ogawa serotypes) and O139 (strain 4260B). The animals were orally administered either OCV placebo (negative control) or OCV at a dose equivalent to 240 times the anticipated human dose. Throughout the administration period, no significant change was detected in clinical signs, body weight, food or water consumption, urinalysis results, hematological and clinical biochemistry test results, organ weights, necropsy, or histopathological examination results. Minor changes were found in hematological and clinical biochemistry tests; however, these changes were within normal ranges. The above results suggest that oral administration of OCV in rats did not induce any toxicologically meaningful changes, and the target organs could not be determined. This study was conducted in accordance with the guidelines established by Good Laboratory Practice (2009-183, KFDA, December 22, 2009) and the OECD Principles of Good Laboratory Practice (1997).

A Case Study on Restaurant Online Coupon Redemption Behavior of Resting Customers / 대한지역사회영양학회지

The purposes this study were to a) analyze the revisiting ratio of resting customers after issuing online coupons, b) compare the characteristics of coupon redemption customers with non-redemption customers. For this study, the customers of M restaurant who did not revisit during the last 8 months were classified as 'resting customers', totaling 4,052 customers. The online coupons, valid for 9 months, were sent via e-mail to those customers. After that, the data collected from those who redeemed the coupon in September 2006 was utilized. As a result of sending the coupon to 4,052 resting customers, 1,288 customers redeemed the coupon during the study period, showing relatively high redemption ratio (31.6%). The average check of customers with the online coupon was decreased by 22% compared with customers without the coupon, but the party size remained almost the same, 2.6 customers, and also the redemption ratio was increasing as the expiration date of the coupon was approaching. The redemption ratio of female (35.3%) was much higher than male (19.2%), representing higher redemption possibility of the female customers by issuing the coupon. The redemption ratio of the twenties (69.1%) was obviously higher than other age groups. Also, the non-redemption ratio of other groups except the twenties was higher than the redemption ratio. The redemption ratio of low-educated was higher, under college degree (58.6%), college degree (35.4%), and over college degree (16.6%). Following the result of the average visiting frequency of redemption customers during last the 8 months was 4.2, the frequency of non-redemption customers was 9.8. The total average visiting of non-redemption customer was 10.5, and that of redemption customers was 8.6. Customers who visited the restaurant less frequently in the past have higher possibility to revisit after receiving the coupon