Application of two occupational health risk assessment methods in enterprises with 1-bromopropane production and utilization / 中国职业医学

OBJECTIVE: To compare the applicability of two risk assessment methods for occupational health risk assessment in enterprises with 1-bromopropane(1-BP) production and utilization. METHODS: Three enterprises with 1-BP production and utilization were selected as the research subjects by a typical sampling method. The exposure concentration of time-weighted average of 1-BP-exposed in worker was detected. The non-carcinogenic health risk of 1-BP was assessed using the USA Environmental Protection Agency(EPA) inhalation risk(EPA assessment model) and the Ministry of Manpower of Singapore(MOM assessment model), and the results were compared. RESULTS: When the EPA method was used for the assessment, the risk assessment results of the four posts in the manufacturing enterprises were all negligible. In the enterprises that use 1-BP, the posts of cleaning machine B and clamping were of medium risk and the other four posts were of low risk based on the occupational exposure limit(OEL) in China used as the reference exposure concentration(RfC). When the 24-hour minimal risk level of USA Agency for Toxic Substances and Disease Registry was used as the RfC, the posts of cleaning machine B and clamping were of extreme high risk; the posts in cleaning machine A and checking were of high risk; the post in the cleaning machine D was of medium risk and the post of cleaning machine C was of low risk. When the MOM assessment model was used for evaluation, the four posts were of low risk in the 1-BP production enterprises. In the enterprises that use 1-BP, the posts of cleaning machine B and clamping were of high risk; the posts of cleaning machine A, cleaning machine D and checking were of medium risk; and the post of cleaning machine C was of low risk. CONCLUSION: When the OEL value is used for risk assessment, the MOM assessment method is more suitable than the EPA assessment method to assess occupational health risks of 1-BP.

Acrylamide-induced Subacute Neurotoxic Effects on the Cerebral Cortex and Cerebellum at the Synapse Level in Rats / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate acrylamide (ACR)-induced subacute neurotoxic effects on the central nervous system (CNS) at the synapse level in rats.</p><p><b>METHODS</b>Thirty-six Sprague Dawley (SD) rats were randomized into three groups, (1) a 30 mg/kg ACR-treated group, (2) a 50 mg/kg ACR-treated group, and (3) a normal saline (NS)-treated control group. Body weight and neurological changes were recorded each day. At the end of the test, cerebral cortex and cerebellum tissues were harvested and viewed using light and electron microscopy. Additionally, the expression of Synapsin I and P-Synapsin I in the cerebral cortex and cerebellum were investigated.</p><p><b>RESULTS</b>The 50 mg/kg ACR-treated rats showed a significant reduction in body weight compared with untreated individuals (P < 0.05). Rats exposed to ACR showed a significant increase in gait scores compared with the NS control group (P < 0.05). Histological examination indicated neuronal structural damage in the 50 mg/kg ACR treatment group. The active zone distance (AZD) and the nearest neighbor distance (NND) of synaptic vesicles in the cerebral cortex and cerebellum were increased in both the 30 mg/kg and 50 mg/kg ACR treatment groups. The ratio of the distribution of synaptic vesicles in the readily releasable pool (RRP) was decreased. Furthermore, the expression levels of Synapsin I and P-Synapsin I in the cerebral cortex and cerebellum were decreased in both the 30 mg/kg and 50 mg/kg ACR treatment groups.</p><p><b>CONCLUSION</b>Subacute ACR exposure contributes to neuropathy in the rat CNS. Functional damage of synaptic proteins and vesicles may be a mechanism of ACR neurotoxicity.</p>

Effects of acrylamide on synaptic plasticity of rat neuron / 中华预防医学杂志

<p><b>OBJECTIVE</b>To explore effects of acrylamide on synaptic plasticity of rat neuron and its mechanisms.</p><p><b>METHODS</b>24 Wistar rats were divided into control and test groups randomly, 12 rats in each group. The ratio of male and female in each group was 1:1. Acrylamide (30 mg/kg) was administered to rats by intraperitoneal injection in test group and normal saline (5 g/kg) was given to rats in control group. The neurobehavioral and pathologic changes of heart, liver, spleen, lung and kidney were observed. Changes of parameters in synapse were recorded by electron microscope. As an important target of synapse, change of Synapsin I was measured by immunohistochemical method.</p><p><b>RESULTS</b>Compared with the control group (male: 1.00 ± 0.00; female: 1.00 ± 0.00), the gait score was increased significantly in ACR treated group (male: 2.50 ± 0.55, t = -7.24, P < 0.01; female: 3.17 ± 0.41, t = -12.19, P < 0.01). No obvious pathological changes of heart, liver, spleen, lung and kidney were found in all rats. Compared with the control group (male: (0.41 ± 0.09) µm; female: (0.40 ± 0.06) µm), the length of active zone of synapse was decreased significantly in ACR treated group (male: (0.15 ± 0.05) µm, t = 6.59, P < 0.05; female: (0.14 ± 0.07) µm, t = 7.26, P < 0.05). The width and postsynaptic density of synapse in ACR treated group had no significant difference with control group. The location of Synapsin I of control group and ACR treated group was both in gray matter of spinal dorsal horn. Compared with the control group (male: 195.40 ± 12.30; female: 195.19 ± 6.71), the concentration of Synapsin I was decreased significantly in ACR treated group (male: 60.90 ± 29.19, t = 10.40, P < 0.05; female: 67.56 ± 20.23, t = 15.65, P < 0.05).</p><p><b>CONCLUSION</b>Neuronal synaptic plasticity was found in damage of nervous system induced by acrylamide in rats, which might be associated with the expression of Synapsin I.</p>

Effect of vinyl chloride on reproductive and endocrine system of male rats / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the effect of vinyl chloride on reproductive and endocrine system of male rats.</p><p><b>METHODS</b>Male SD rats were administered with vinyl chloride at dose of (0, 10, 100, 1000 mg/kg) for 14 and 28 days, respectively. The levels of testosterone (T), inhibin B, luteinizing hormone (LH), follicle stimulating hormone (FSH) and estradiol (E2) were measured in serum and testis homogenates. Histopathological examinations were performed for testis with electron microscopy.</p><p><b>RESULTS</b>Compared with the control group after 14-day exposure, T and E2 serum levels of 1000, 100, 10 mg/kg groups decreased, InhB and LH levels of three dose groups increased. LH serum levels of 100 mg/kg increased significantly statistically compared with control group (P < 0.05). After 28-day exposure, T serum levels of 100, 1000 mg/kg groups were (10.90 +/- 1.56), (8.52 +/- 2.85) ng/ml respectively (P < 0.05), InhB serum levels of 100, 1000 mg/kg groups were (31.40 +/- 6.21), (28.39 +/- 5.67) pg/ml respectively. Both of T and InhB serum levels of 100, 1000 mg/kg groups decreased significantly (P < 0.05). Serum FSH levels of 10, 100, 1000 mg/kg groups decreased significantly compared with control group (P < 0.05). Compared with groups of 14-day exposure, serum InhB and LH levels of 10, 100, 1000 mg/kg groups decreased significantly statistically after 28 days. T and InhB testis levels of 100, 1000 mg/kg groups were 8.05 +/- 2.19),(6.75 +/- 1.94) ng/mg pro and (39.32 +/- 5.55), (35.53 +/- 8.71) pg/mg pro respectively, which decreased significantly compared with control group (P < 0.05). Leydig cell and Sertoli cell were damaged according to histopathological examinations.</p><p><b>CONCLUSION</b>Vinyl chloride has adverse effects on reproductive and endocrine system of male rats and may change their serum and testis homogenate levels of hormones.</p>