Naohide Shinohara

Symptom profile of multiple chemical sensitivity in actual life.

Objective: This study was conducted to confirm the definition of multiple chemical sensitivity (MCS) in actual life: that multiple symptoms are provoked in multiple organs by exposure to, and ameliorated by avoidance of, multiple chemicals at low levels. We used the Ecological Momentary Assessment to monitor everyday symptoms and the active sampling and passive sampling methods to measure environmental chemical exposure. Methods: Eighteen patients with MCS, diagnosed according to the 1999 consensus criteria, and 12 healthy controls participated in this study. Fourteen patients and 12 controls underwent 1-week measurement of physical and psychologic symptoms and of the levels of exposure to various chemicals. Linear mixed models were used to test the hypotheses regarding the symptom profile of MCS patients. Results: Some causative chemicals were detected in 11 of 14 MCS patients. Two other patients did not report any hypersensitivity episodes, whereas passive sampling showed far less exposure to chemicals than control subjects. Another subject reported episodic symptoms but was excluded from the following analyses because no possible chemical was detected. Eleven of the 17 physical symptoms and all four mood subscales examined were significantly aggravated in the interview based on “patient-initiated symptom prompts.” On the other hand, there were no differences in physical symptoms or mood subscales between MCS patients and control subjects in the interview based on “random prompts.” Conclusions: MCS patients do not have either somatic or psychologic symptoms under chemical-free conditions, and symptoms may be provoked only when exposed to chemicals. AS = active sampling; AS–PS method = active sampling and passive sampling methods; CAS = the concentration of exposure estimated by the AS method; CFS = chronic fatigue syndrome; CPS = the concentration of exposure estimated by the PS method; CS = chemical sensitivity; DAMS = Depression and Anxiety Mood Scale; DNPH = 2,4-dinitrophenyl-hydrazine; ED = electronic diary; EESI = Environmental Exposure and Sensitivity Inventory; EMA = Ecological Momentary Assessment; FM = fibromyalgia; M.I.N.I. = Mini International Neuropsychiatric Interview; MCS = multiple chemical sensitivity; PS = passive sampling; RSD = relative standard deviation; RSDAS = RSD of repeatability test in the AS method; RSDPS = RSD of repeatability test in the PS method; VOCs = volatile organic compounds.

Identification of responsible volatile chemicals that induce hypersensitive reactions to multiple chemical sensitivity patients

Multiple chemical sensitivity (MCS) has become a serious problem as a result of airtight techniques in modern construction. The mechanism of the MCS, however, has not been clarified. Responsible chemicals and their exposure levels for patients hypersensitive reactions need to be identified. We measured the exposure of 15 MCS patients to both carbonyl compounds and volatile organic compounds (VOCs) that may induce hypersensitive reactions. The exposures of those not suffering from MCS (non-MCS individuals) were also measured at the same time. To characterize the chemicals responsible for MCS symptoms, we applied a new sampling strategy for the measurement of carbonyls and VOCs using active and passive sampling methods. The results of our study clearly demonstrated that the chemicals responsible for such hypersensitive reactions varied from patient to patient. Moreover, the concentrations during hypersensitive symptoms, which were apparent in some of the MCS patients, were far below both the WHO and the Japanese indoor guidelines. The average exposure levels of MCS patients within a 7-day period were lower than those of paired non-MCS individuals except for a few patients who were exposed to chemicals in their work places. This result indicates that the MCS patients try to keep away from exposures to the chemical compounds that cause some symptoms.

Field validation of an active sampling cartridge as a passive sampler for long-term carbonyl monitoring

Abstract A carbonyl sampler originally designed for the active sampling method (Sep-Pak XPoSure) was used for long-term passive sampling, and its applicability as a passive sampler was examined through field experiments. The uptake rates of passive sampling were determined experimentally from collocated passive and active samplings for various sampling periods. The obtained uptake rates of formaldehyde, acetaldehyde, and acetone were 1.48, 1.23, and 1.08 mL/min, respectively. These uptake rates were consistent for a wide range of the sampling term (12 hr–2 weeks). Uptake rates of each carbonyl were proportional to the diffusion coefficients of each. Therefore, the ratios of diffusion coefficients were used to calculate the uptake rates of carbonyls for which the rates were not determined experimentally. Lower limits of determination were 2.16–17.5 μg/m3 for 2-week sampling. It was confirmed that 2-week monitoring of carbonyl concentrations up to 118–229 μg/m3 was possible. Relative standard deviations of the passive method generated from the repeatability test were 2–12.3% error for five samplings, and the recovery efficiencies were larger than 90%. Thus, the passive sampler was found to be highly suitable for long-term monitoring of carbonyl compounds.

Distribution of Indoor Concentrations and Emission Sources of Formaldehyde in Japanese Residences

Since the 1990s, tight sealing of buildings to save energy and new types of building materials have caused air pollution problems inside many houses in Japan. Many people are suffering from sick building syndrome (SBS), sick house syndrome (SHS), and multiple chemical sensitivity (MCS) in such houses. Formaldehyde has been reported to be one of the chemical substances responsible for causing SBS, SHS, and MCS symptoms, such as eye irritation, respiratory tract irritation, dizziness, fatigue, and neurotoxicity (Kim et al., 2000; Paustenbach et al., 1997; Shinohara et al., 2004). In addition, formaldehyde was reported to be a human carcinogen (IARC 2006). Formaldehyde has been commonly used in a raw material for synthetic resins such as urea resin, melamine resin, phenolic resin, and synthetic rubber. These resins were used as adhesives in plywood, particle board, and wallpapers in building materials and furniture. The resins react with water to form formaldehyde due to hydrolysis. Formaldehyde has also been used as a bleaching agent and fungicide in wallpaper and curtains. Residual and formed formaldehyde can be emitted from building materials and furniture to the indoor environment of buildings. Indoor concentrations of formaldehyde are higher in summer than in winter. In Japan, concentration levels were reported to be 39.9 ± 33 μg m-3 (Amagai et al., 2000), 34.7 ± 23 μg m-3 (Tokyo Metropolitan Government Bureau of Public Health, 2002), and 78.9 ± 22 μg m-3 (Shinohara et al., 1999) in summer, while concentrations in winter were 21.7 ± 14 μg m-3 (Tokyo Metropolitan Government Bureau of Public Health, 2002), 58.6 ± 20 μg m-3 (Shinohara et al., 1999), and 17.6 ± 1.8 μg m-3 (Sakai et al., 2004). The formaldehyde concentrations are higher in new houses than those in older houses. The geometric means (GM) of indoor formaldehyde concentrations in new houses were 64.9 μg m-3 (Tokyo Metropolitan Institute of Public Health, 2002) and 84.2 μg m-3 (Tateno et al., 1999), while those in old houses were 37.7 μg m-3 (Tokyo Metropolitan Institute of Public Health, 2002)

Reductions in commuter exposure to volatile organic compounds in Mexico City due to the environmental program ProAire2002–2010

We investigated commuter exposure to volatile organic compounds in the metropolitan area of Mexico City in 2011 in private car, microbus, bus, metro, metrobus, and trolley bus. A similar survey was conducted in 2002 before initiation of the ProAire2002–2010 program aimed at reducing air pollution. Formaldehyde, acetaldehyde, benzene, toluene, ethylbenzene, m/p-xylene, and o-xylene were sampled while traveling during the morning rush hour in May 2011. Compared with the 2002 survey, in-vehicle concentrations were substantially lower in 2011, except for formaldehyde in microbuses (35% higher than in 2002). The reductions were 17–42% (except microbuses), 25–44%, 41–61%, 43–61%, 71–79%, 80–91%, and 79–93% for formaldehyde, acetaldehyde, benzene, toluene, ethylbenzene, m/p-xylene, and o-xylene, respectively. These reductions are considered to be the outcome of some of the actions in the ProAire2002–2010 program. In some microbuses, use of liquid petroleum gas may have increased in-vehicle formaldehyde concentrations. The reduction in predicted excess cancer incidence of commuters because of ProAire2002–2010 was estimated to be 1.4 cases/yr. In addition, if every microbus commuter changed their transport mode to bus, metro, or metrobus in the future, the estimated excess cancer incidence of commuters could be further decreased from 6.4 to 0.88–2.2 cases/year.