Background: Although biocides at low concentrations have been used to control pests, they can be more harmful than industrial chemicals as humans are directly and frequently exposed to such biocides. Benzalkonium chloride (BAC or BKC) is a non-toxic substance used to control pests. Recently, BAC has been increasingly used as a component in humidifier disinfectants in Korea, raising a serious health concern. Moreover, it poses significant health hazards to workers handling the chemical because of direct exposure. In the present study, we aimed to evaluate the respiratory toxicity of BAC due to its inhalation at exposure concentrations of 0.8 (T1 group), 4 (T2 group) and 20 (T3 group) mg/m 3. Results: In our previous study on the acute inhalational toxicity of BAC, bleeding from the nasal cavity was observed in all the rats after exposure to 50 mg/m 3 BAC. Therefore, in this study, 20 mg/m 3 was set as the highest exposure concentration, followed by 4 and 0.8 mg/m 3 as the medium and low concentrations for 6 h/day and 14 days, respectively. After exposure, recovery periods of 2 and 4 weeks were provided. Additionally, alveolar lavage fluid was analyzed in males of the BAC-exposed groups at the end of exposure and 2 weeks after exposure to evaluate oxidative damage. In the T3 group exposed to BAC, deep breathing, hoarseness, and nasal discharge were observed along with a decline in feed intake and body weight, and nasal discharge was also observed in the T1 and T2 groups. ROS/RNS, IL-1β, IL-6, and MIP-2 levels decreased in a concentration-dependent manner in the bronchoalveolar lavage fluid. Histopathological examination showed cellular changes in the nasal cavity and the lungs of the TI, T2, and T3 groups. Conclusions: As a result, it was confirmed that the target organs in the respiratory system were the nasal cavity and the lungs. The adverse effects were evaluated as reversible responses to oxidative damage. Furthermore, the no observed adverse effect level was found to be less than 0.8 mg/m 3 and the lowest benchmark dose was 0.0031 mg/m 3. Accordingly, the derived no-effect level of BAC was calculated as 0.000062 mg/m 3 .

Background: A previous study suggested an association between low caloric intake(CI), negative nitrogen balance, and poor outcome after subarachnoid hemorrhage(SAH). Objective of this multinational, multicenter study was to investigate whether clinical outcomes vary by protein intake(PI) or CI in SAH patients adjusting for the nutritional risk as judged by the modified NUTrition Risk in the Critically Ill (mNUTRIC) score. Methods: The International Nutrition Survey(INS) 2007-2014 was utilized to describe the characteristics, outcomes and nutrition use. A subgroup of patients from 2013 and 2014(when NUTRIC score was captured) examined the association between CI and PI and time to discharge alive(TTDA) from hospital using Cox regression models, adjusting for nutrition risk classified by the mNUTRIC score as low(0-4) or high(5-9). Results: There were 489 SAH patients(57% female with a mean ± SD age 57.5 ± 13.9 years, BMI of 25.9 ± 5.3 kg/m2 and APACHE-2 score 19.4 ± 7.0. Majority(85%) received enteral nutrition(EN) only, with a time to initiation of EN of 35.4 ± 35.2 hours. 64% had EN interrupted. Patients received a CI of 14.6 ± 7.1 calories/kg/day and PI 0.7 ± 0.3 grams/kg/day corresponding to 59% and 55% of total prescribed CI and PI respectively. In the 2013 and 2014 subgroup there were 226 SAH patients with a mNUTRIC score of 3.4 ± 1.8. Increased CI and PI were associated with faster TTDA among high mNUTRIC patients(HR per 20% of prescription received = 1.34[95% CI,1.03 -1.76] for CI and 1.44[1.07 -1.93] for PI), but not low mNUTRIC patients(CI: HR = 0.95[0.77 -1.16] PI:0.95[0.78 -1.16]). Conclusions: Results from this multicenter study found that SAH patients received under 60% of their prescribed CI and PI. Further, achieving greater CI and PI in hi risk SAH patients was associated with improved TTDA. mNUTRIC serves to identify SAH patients that benefit most from artificial nutrition and efforts to optimize protein and caloric delivery in this subpopulation should be maximized.

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