Prevalence and interannual changes in multiple chemical sensitivity in Japanese workers

Objective

We aimed to evaluate the prevalence rates and interannual fluctuations in multiple chemical sensitivity (MCS) in Japanese workers.

Methods

We assessed MCS using the Quick Environmental Exposure and Sensitivity Inventory, employing both Miller and Japanese criteria. Workers of two manufacturing companies located in Kyushu, Japan, were assessed, with company A surveyed in 2003, 2006 and 2011, and company B in 2003 and 2011.

Results

In company A, the Miller criteria-based MCS prevalence rate was higher in 2011 than in 2003, and according to the Japanese criteria, it was higher in 2011 than 2006. In company B, the Miller criteria-based MCS prevalence rate was lower in 2011 than in 2003.

Conclusion

The results indicated that MCS exists among industrial workers in Japan. We found no statistically significant interannual changes in MCS rates.     

Case-control study of multiple chemical sensitivity, comparing haematology, biochemistry, vitamins and serum volatile organic compound measures

BACKGROUND: Multiple chemical sensitivity (MCS), although poorly understood, is associated with considerable morbidity. AIM: To investigate potential biological mechanisms underlying MCS in a case-control study. METHODS: Two hundred and twenty-three MCS cases and 194 controls (urban females, aged 30-64 years) fulfilled reproducible eligibility criteria with discriminant validity. Routine laboratory results and serum levels of volatile organic compounds (VOCs) were compared. Dose-response relationships, a criterion for causality, were examined linking exposures to likelihood of case status. RESULTS: Routine laboratory investigations revealed clinically unimportant case-control differences in means. Confounder-adjusted odds ratios (OR) showed MCS was negatively associated with lymphocyte count and total plasma homocysteine, positively associated with mean cell haemoglobin concentration, alanine aminotransferase and serum vitamin B6, and not associated with thyroid stimulating hormone, folate or serum vitamin B12. More cases than controls had detectable serum chloroform (P = 0.001) with the OR for detectability 2.78 (95% confidence interval = 1.73-4.48, P < 0.001). Chloroform levels were higher in cases. However, cases had significantly lower means of detectable serum levels of ethylbenzene, m&p-xylene, 3-methylpentane and hexane, and means of all serum levels of 1,3,5- and 1,2,3-trimethylbenzene, 2- and 3-methylpentane, and m&p-xylene. CONCLUSIONS: Our findings are inconsistent with proposals that MCS is associated with vitamin deficiency or thyroid dysfunction, but the association of lower lymphocyte counts with an increased likelihood of MCS is consistent with theories of immune dysfunction in MCS. Whether avoidance of exposures or different metabolic pathways in cases explain the observed lower VOC levels or the higher chloroform levels should be investigated.     

基于多元逐步回归分析的川、浙、津三地慢性病患者住院费用影响因素研究

目的 探讨川、浙、津三地慢性病患者住院费用状况及影响因素。 方法 于2017年9月-2019年7月采用分层抽样和随机抽样结合的方法,对三地共559名慢性病患者进行了问卷调查。基于SPSS22.0和STATA14.0,利用Kruskal-Wallis H、Mann-Whitney U检验、多元逐步回归模型进行影响因素分析。 结果 慢性病患者平均住院费用为11578.9元。年龄（b=0.024）、婚姻状况（已婚:b=-0.856;丧偶:b=0.919）、一年内是否健康体检（b=-0.350）、慢性病种类（消化系统疾病:b=0.370;脑血管疾病:b=0.462;癌症:b=0.559）、多重慢病(b=0.372)、住院天数(b=0.024)是四川慢性病患者住院费用的影响因素（P<0.05）;月收入水平(3000~4000:b=0.290;>4000:b=0.357)、医疗保险(城镇职工医疗保险:b=-0.429;城镇居民医疗保险:b=0.300)、慢性病种类（糖尿病:b=0.374,癌症:b=1.005）、多重慢病（b=0.364）、住院天数（b=0.018）是浙江慢性病患者住院费用的影响因素（P<0.05）;户口性质（b=0.439）、年龄（b=0.018）、一年内是否健康体检（b=-0.399）、慢性病种类（呼吸系统疾病:b=0.900;癌症:b=1.049）、住院天数（b=0.018）是天津慢性病患者住院费用的影响因素（P<0.05）。结论 为有效降低慢性病患者住院费用,建议三个地区均加强慢性病筛查与预防,鼓励定期体检;重视老年慢性病患者健康教育;按病种制定标准住院日。四川应重视慢性病患者情感支持,提高饮食管理水平。浙江应完善医保补偿机制,提高健康公平性。天津则需加强空气治理,并关注农村弱势群体健康问题。     

Effect of exposure to volatile organic compounds on plasma levels of neuropeptides, nerve growth factor and histamine in patients with self-reported multiple chemical sensitivity

Plasma levels of substance P, vasoactive intestinal peptide and nerve growth factor, but not histamine, were elevated in patients with self-reported multiple chemical sensitivity (sMCS). Exposure to volatile organic compounds (VOC) increased plasma levels of all parameters in these patients, while it had no effect in normal subjects or patients with atopic eczema/dermatitis syndrome (AEDS). Exposure to VOC also enhanced skin wheal responses induced by histamine in patients with sMCS, while it failed to do so in normal or AEDS subjects. These results indicate that exposure to VOC may enhance neurogenic inflammation with concomitant enhancement of histamine-induced responses.