Advances on toxicity of polyhexamethyl guanidine / 环境与职业医学

Polyhexamethyl guanidine (PHMG) is a widely used guanidine disinfectant. Since a lung injury incident induced by humidifier disinfectant (PHMG was identified as a main component) was reported in Korea, its inhalation toxicity has attracted the attention of researchers. At present, there are few domestic studies on inhalation toxicity of PHMG. In this paper, based on the domestic and foreign studies of PHMG, the toxicities of PHMG, including inhalation toxicity and associated toxic mechanism, and other potential toxicities, such as liver toxicities, cardiovascular toxicity, immunotoxicity, and reproductive and developmental toxicity, were systematically introduced, revealing that the effects of use of PHMG in a non-standard manner on the body and its possible mechanisms, which could provide reference for the use of PHMG properly and to lay a theoretical foundation and provide a scientific basis for follow-up study.

Study on the subacute inhalation toxicity of ivermectin TC in rats / 中国比较医学杂志

Objective To study the subacute inhalation toxicity of Ivermectin TC, and obtain its non-observed adverse effect level(NOAEL).Methods It was performed on the doses of Ivermectin TC 190, 380, 750 mg/m3, the solvent control group (0.03%Tween-80 solution) , the control group and additional group ( there were 6 female and 6 male Sprague-Dawley rats for each group) .The animals inhaled with nose-only exposure for 4 weeks (4 h/d, 5 d/week) .The additional group should be observed another 14 days after exposing.At the end of experiment, the rats were killed, the routine and biochemical detection, the body weight and organ to body weight ratios were all measured.Results In the high exposure group, clinical signs of rats included hair fluffy, dull, salivation, tremors were recorded at the exposure period;in female rats, feed efficiency was decreased, ALT and liver to body weight ratio were increased; in male rats, BUN and ALT were increased, CHOL and body weight for the 4th week were decreased.Histopathological examinations revealed that swelling in the liver cell was seen in some female rats at high exposure group.Conclusion The results suggested that the NOAEL of Ivermectin TC in SD rats was 380 mg/m3(4 h/d for 28 days).

Study on acute inhalation toxicity of Luowei,a plant molluscacide / 中国血吸虫病防治杂志

Objective To study the acute inhalation toxicity of 50% Luowei,a plant molluscacide,in rats. Methods Twenty adult Wistar rats,half male and half female,were given of 5000 mg/m3 of 50% Luowei through a dynamic inhalation de?vice and the death and recovery of the rats were observed within 14 days,and LC50 was drawn. Results After exposure,the ac?tivities of the rats decreased and a few individual animals had scratching symptom,but the symptom disappeared after the expo?sure. No animals died during the whole observation period. Therefore,the acute inhalation LC50 was greater than 5000 mg/m3 for rats,and Luowei belonged to low toxicity level. Conclusions 50% Luowei will not cause animal death if it is inhaled into ani?mal body. However,people still need to wear protective equipment in production and use.

Subchronic Inhalation Toxicity Study of n-pentane in Rats

OBJECTIVES: This study was conducted in order to obtain information concerning the health hazards that may result from a 13 week inhalation exposure of n-pentane in Sprague-Dawley rats. METHODS: This study was conducted in accordance with the Organization for Economic Co-operation and Development (OECD) guidelines for the testing of chemicals No. 413 'Subchronic inhalation toxicity: 90-day study (as revised in 2009)'. The rats were divided into 4 groups (10 male and 10 female rats in each group), and were exposed to 0, 340, 1,530, and 6,885 ppm n-pentane in each exposure chamber for 6 hour/day, 5 days/week, for 13 weeks. All of the rats were sacrificed at the end of the treatment period. During the test period, clinical signs, mortality, body weights, food consumption, ophthalmoscopy, locomotion activity, urinalysis, hematology, serum biochemistry, gross findings, organ weights, and histopathology were assessed. RESULTS: During the period of testing, there were no treatment related effects on the clinical findings, body weight, food consumption, ophthalmoscopy, urinalysis, hematology, serum biochemistry, gross findings, relative organ weight, and histopathological findings. CONCLUSION: The no-observable-adverse-effect level (NOAEL) of n-pentane is evaluated as being more than 6,885 ppm (20.3 mg/L) in both male and female rats. n-pentane was not a classified specific target organ toxicity in the globally harmonized classification system (GHS).

In vivo Genotoxicity of Silver Nanoparticles after 90-day Silver Nanoparticle Inhalation Exposure

OBJECTIVES: The antimicrobial activity of silver nanoparticles has resulted in their widespread use in many consumer products. Yet, despite their many advantages, it is also important to determine whether silver nanoparticles may represent a hazard to the environment and human health. METHODS: Thus, to evaluate the genotoxic potential of silver nanoparticles, in vivo genotoxicity testing (OECD 474, in vivo micronuclei test) was conducted after exposing male and female Sprague-Dawley rats to silver nanoparticles by inhalation for 90 days according to OECD test guideline 413 (Subchronic Inhalation Toxicity: 90 Day Study) with a good laboratory practice system. The rats were exposed to silver nanoparticles (18 nm diameter) at concentrations of 0.7 x 10(6) particles/cm3 (low dose), 1.4 x 10(6) particles/cm3 (middle dose), and 2.9 x 10(6) particles/cm3 (high dose) for 6 hr/day in an inhalation chamber for 90 days. The rats were killed 24 hr after the last administration, then the femurs were removed and the bone marrow collected and evaluated for micronucleus induction. RESULTS: There were no statistically significant differences in the micronucleated polychromatic erythrocytes or in the ratio of polychromatic erythrocytes among the total erythrocytes after silver nanoparticle exposure when compared with the control. CONCLUSION: The present results suggest that exposure to silver nanoparticles by inhalation for 90 days does not induce genetic toxicity in male and female rat bone marrow in vivo.

Acute and Subchronic Inhalation Toxicity of n-Octane in Rats

OBJECTIVES: We have investigated the toxic effects of the inhalation of subchronic and acute levels of n-octane. METHODS: The rats were exposed to n-octane of 0, 2.34, 11.68 and 23.36 mg/L (n = 5 rats/group/gender) in an acute inhalation test (Organization for Economic Co-operation and Development (OECD) TG 403), or to 0, 0.93, 2.62 and 7.48 mg/L (n = 10 rats/group/gender) for a subchronic inhalation test (OECE TG 413), to establish a national chemical management system consistent with the Globally Harmonized Classification System (GHS). RESULTS: Acutely-exposed rats became lethargic but recovered following discontinuation of inhalation. Other clinical symptoms such as change of body weight and autopsy finds were absent. The LC50 for the acute inhalation toxicity of n-octane was determined to exceed 23.36 mg/L and the GHS category was 'not grouping'. Subchronically-treated rats displayed no significant clinical and histopathological differences from untreated controls; also, target organs were affected hematologically, biochemically and pathologically. Therefore, the no observable adverse effect level was indicated as exceeding 7.48 mg/L and the GHS category was 'not grouping' for the specific target organ toxicity upon repeated exposure. CONCLUSION: However, n-octane exposure should be controlled to be below the American Conference of Industrial Hygienists recommendation (300 ppm) to prevent inhalation-related adverse health effects of workers.

Inhalation Toxicity of Indoors Volatile Organic Compounds in Mice / 环境与健康杂志

Objective To study the inhalation toxicity of volatile organic compounds in mice. Methods The VOC mixture was prepared according to the monitoring data on indoors air. NIH mices were exposed to the gaseous mixture at the doses of 80.00 mg/m3,64.00 mg/m3,51.28 mg/m3,40.96 mg/m3,32.79 mg/m3 and 26.21 mg/m3 to determine the acute toxicity,and at the doses of 10.75 mg/m3,5.38 mg/m3,2.69 mg/m3 to examine the toxic effect on the weight,organ coefficient,the activity of GSH-Px and SOD and the contents of MDA in the serum. The accumulative toxicity was determined. Results The LD50 of acute inhalation toxicity was 53.74 mg/m3.After exposed to this gaseous mixture for 30 days,the body weight decreased significantly,the organ coefficient of liver and kidney changed,and the activity of GSH-Px and SOD decreased,the contents of MDA in serum increased. The accumulation coefficient was above 5. Conclusion This VOC mixture has weak accumulation toxicity in mice,but have some other toxicity.