Occupational exposure limit of trimethyltin chloride in workplace air / 中国职业医学

OBJECTIVE: To establish the occupational exposure limit for trimethyltin chloride(TMT) in workplace air. METHODS:According to the GBZ/T 210.1-2008 Guide for Establishing Occupational Health Standards--Part 1: Occupational Exposure Limits for Airborne Chemicals in the Workplace, the relevant literatures on toxicology, population epidemiology and foreign occupational exposure limit of TMT were collected and analyzed. A total of 276 workers with TMT occupational exposure were selected as the exposure group and 25 workers without TMT occupational exposure were selected as the control group.Worksite survey of occupational health and occupational medical examination were carried out. Combined with the literature data, the occupational exposure limit of TMT in the workplace air was calculated by using the 90% medical reference level(internal exposure limit) of the urine TMT level of workers who exposed to TMT without moderate hypokalemia. RESULTS: The time-weighted average of TMT in the workplace air is 0.100 mg/m~3 and the short-term exposure limit is 0.200 mg/m~3 in the United States based on total organic tin. The highest concentration of TMT in the workplace air in Germany is 0.005 mg/m~3. The literature data analysis results showed that the incubation period of TMT poisoning is mostly 3-6 days, and the main symptoms of TMT poisoning are hypokalemia in the early stage, followed by neuropsychiatric symptoms such as headache, memory loss and aggressive behavior. The median(M) and the 0-100 th percentile(P_0-P_(100)) of exposure to TMT were 8.35(< 0.20-91.40) μg/m~3 in the exposure group. The individual TMT exposure level of workers in different positions from high to low were crushing, granulation, withdrawal and assembly positions. The M(P_0-P_(100)) of urinary TMT level in the exposure group was 16.94(<0.50-591.14) μg/L. There was a positive correlation between the individual TMT exposure level and urine TMT level in the exposure group(Spearman correlation coefficient=0.62, P<0.01). The detection rate of hypokalemia in the exposure group was higher than that in the control group(26.1% vs 4.0%, P < 0.05). However, there was no significant difference in the detection rate of moderate hypokalemia between the two groups(3.3% vs 0.0%, P>0.05). The 90% medical reference value of urine TMT was 89.90 μg/L in workers exposed to TMT without moderate hypokalemia. CONCLUSION: In order to prevent acute hypokalemia damage caused by TMT, we recommended that the occupational exposure limit of TMT in the workplace air should be set at 0.025 mg/m~3 in China, and this limit should be the maximum allowable concentration.

The compilation and explanation of Technical Plan for Emergency Treatment of Acute 1,2-Dichloroethane Poisoning / 中国职业医学

Acute 1,2-dichloroethane poisoning causes serious illness, deaths and is a social event of great influence. The compilation of Technical Plan for Emergency Treatment of Acute 1,2-Dichloroethane Poisoning provides scientific guidance for effective treatment of 1,2-dichloroethane poisoning events. The plan describes in detail the specific practice and technical requirements of six links in the process of handling emergency of acute 1,2-dichloroethane poisoning, including accident investigation and treatment, risk assessment, collection and testing of samples, medical treatment, health monitoring and emergency response, et al. The key contents of individual protection requirements, investigation content, etiology determination, medical assistance and health education in the disposal of poisoning incidents were clarified, and the procedures and requirements of health education were added. The technical scheme is scientific, objective and operable, which can provide scientific guidance for the effective treatment of 1,2-dichloroethane poisoning accidents.

Research on the clinical pathway on chronic mild occupational cadmium poisoning / 中国职业医学

OBJECTIVE: To establish the clinical pathway of chronic mild occupational cadmium poisoning,and to promote the application of clinical pathway in the treatment of occupational diseases. METHODS: Chronic mild occupational cadmium poisoning was selected as a disease for a pilot study based on GBZ 17-2015 Diagnosis of Occupational Cadmium Poisoning. The diagnosis and treatment scheme and the clinical pathway were developed based on the theory of evidencebased medicine and expert consultation. It was then used and evaluated in clinical practice in several hospitals. RESULTS: The content of clinical pathway of chronic mild occupational cadmium poisoning included the standard in-hospital treatment process protocol,the clinical pathway forms and the consent document for patients. The clinical application of the pathway significantly improved the outcome of treatment,shortened hospital stays and effectively control hospitalization expenses.CONCLUSION: The clinical pathway for chronic mild occupational cadmium poisoning is rational and feasible. The result confirms that the clinical pathway may have good application prospect for the treatment of occupational diseases.

Study on activities and protein and gene expression of renal H(+)-K(+)-ATPase in rats subchronic exposed to trimethyltin chloride / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the activity, protein and gene expression of renal HK-ATPase (HKA) in rats subchronic exposed to trimethyltin chloride (TMT).</p><p><b>METHODS</b>In subchronic toxic test (14-week), 55 female SD rats (age, 6 weeks) were divided randomly into 5 groups: control, low, medium, high and super high dosage, respectively, which drank water with TMT of 0, 8.20, 32.81, 131.25 and 262.50 microg x kg(-1) x d(-1) for 14 weeks. Then serum K+ levels were measured; the activities of HK-ATPase (HKA) in kidneys were detected by the method of determinated phosphorus content; Western Blot assay and real-time PCR were used to exam the protein and mRNA expression levels of HKA in kidneys, respectively.</p><p><b>RESULTS</b>The serum K+ level in super-high dosage group was (5.6 +/- 0.4) mmol/L, which was significantly lower than that [(6.9 +/- 0.3) mmol/L] in control group (P < 0.01). The HKA enzymatic activity of kidneys in low and super high dosage groups was 4.50 +/- 1.45 and 4.55 +/- 0.72 micromolPi x mg prot(-1)h(-1), respectively, which were significantly lower than that (6.55 +/- 0.77 micromol Pi x mg prot(-1) h(-1)) in control group (P < 0.05).</p><p><b>CONCLUSION</b>When rats were exposed subchronic to TMT, the renal HKA activity could reduce, but the expression levels of HKA protein and mRNA did not decrease.</p>

Short-term central nervous system symptoms and changes in blood indicators after benzene poisoning in rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the central nervous system symptoms and alterations in the blood indicators in rats within a short term after benzene poisoning.</p><p><b>METHOD</b>Twenty-four female SD rats were randomized into 4 equal groups to receive intraperitoneal injection of low-, medium- or high-dose benzene (39.05, 78.11, and 234.33 mg/kg, respectively) or peanut oil. Blood samples were taken from the rats via the femoral artery 24 h after the injections for routine blood test and liver and kidney function test.</p><p><b>RESULTS</b>Intraperitoneal injection of benzene at a high dose, but not at a low or medium dose, caused obvious symptoms in the central nervous system. Benzene either at a low or medium dose did not produce obvious changes in routine blood test or liver and kidney function test as compared with the control group, but a high dose resulted in significant changes in WBC, PLT, ALT and AST (P<0.05). Abnormalities in the renal function were found in none of the groups (P>0.05).</p><p><b>CONCLUSION</b>Exposure to high-dose benzene can result in abnormalities in the central nervous system, routine blood indicators and liver function, but does not obviously affect the kidney function in rats.</p>

The level of serum tumor necrosis factor-alpha and epidermal growth factor in patients with medicament-like dermatitis by trichloroethylene and its clinical significance / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the level of tumor necrosis factor alpha (TNF-alpha) and epidermal growth factor (EGF) in patients with medicament-like dermatitis by trichloroethylene (DMLT).</p><p><b>METHODS</b>Using radioimmunoassay methods, serum TNF-alpha, EGF were measured in 39 patients with DMLT and in 20 controls.</p><p><b>RESULTS</b>The levels of serum TNF-alpha, EGF in patients with DMLT [(0.278 +/- 0.092) ng/L, (6.71 +/- 2.28) microg/L, respectively] were significantly higher than those of the controls [(0.128 +/- 0.029) ng/L, (4.31 +/- 1.13) microg/L respectively, P<0.05, P<0.01].</p><p><b>CONCLUSION</b>The increased levels of serum TNF-alpha, EGF in patients with DMLT may be related to the following causes: (1) Trichloroethylene and its metabolite may irritate the macrophagocyte and monocyte in human body to release TNF-alpha into blood stream; (2) Severe damage of epithelial tissue in patients with DMLT may promote more EGF synthesis to accelerate the regeneration and repair of epithelial tissue.</p>

Studies on hypokalemia induced by trimethyltin chloride / 生物医学与环境科学（英文）

<p><b>OBJECTIVES</b>To determine the possible relationship between plasma potassium concentration and severity of acute trimethyltin chloride (TMT) poisoning and to assess the mechanism of TMT induced hypokalemia.</p><p><b>METHODS</b>SD rats were treated with various dosages of TMT (i.p.). All the indices were measured and analysed for determining their possible relations with plasma K+.</p><p><b>RESULTS</b>With increase of dosage, the plasma K+ level dropped rapidly, and deaths appeared more quickly. The LD50 of TMT (i.p.) was 14.7 mg/kgbw. In the low dosage group (10 mg/kgbw), the plasma K+ level dropped slowly with the lowest dosage on day 6 (4.85 mmol/L). It rose again on day 11 (5.06 mmol/L), and recovered on day 28. The poisoning signs corresponded with decline of the span of K+ level. The plasma Na+ level dropped half an hour after TMT treatment, but recovered 24 h later. In the high dosage group (46.4 mg/kgbw), the levels of plasma K+ and Na+ fell rapidly within half an hour (P < 0.05), the intracellular potassium concentration of RBC did not decrease obviously (P > 0.05), the activities of Na(+)-K(+)-ATPase and Mg(2+)-ATPase in RBC membrane were depressed remarkably (P < 0.01, P < 0.05, respectively), the plasma aldosterone concentrations rose as high as tenfold (P < 0.01), the arterial blood pH fell from 7.434 to 7.258 (P < 0.01), pCO2 was raised from 29.62 to 45.33 mmHg (P < 0.01). In the 24 h urine test, when rats were treated with TMT (21.5 mg/kgbw, i.p.), urine volume, urinary potassium, sodium and chloride increased significantly in comparison with those in the controls (P < 0.01).</p><p><b>CONCLUSION</b>TMT could induce hypokalemia in SD rats. The available evidence suggests that TMT can induce acute renal leakage of potassium. At the same time, a significant rise of plasma aldosterone may play an important role in promoting potassium leakage from kidney to result in severe hypokalemia with inhaling acid-base abnormalities produced, which aggravate the poisoning symptoms. In the end the rats would die of respiratory failure.</p>