Diallyl disulfide (DADS) and allyl methyl sulfide (AMS) have been known as a metabolic product of sulfur-containing foods, typically garlic. The odour of such organosulfur compounds following garlic ingestion is often considered as an unpleasant element. Although previous studies have identified the DADS and AMS associated with garlic breath, no study has been reported on the determination of both compounds emanating from human skin surface. This study aimed to demonstrate the effect of garlic ingestion on the dermal emissions of DADS and AMS using a passive flux sampler coupled with gas chromatography-mass spectrometry. Firstly, baseline levels were investigated for 30 healthy volunteers in their daily life. The results of 1 h-sampling at the forearm showed the emission fluxes of both compounds followed the lognormal distribution with a geometric mean of 0.18 ng cm⁻² h⁻¹ for DADS and 0.22 ng cm⁻² h⁻¹ for AMS. Subsequently, the garlic ingestion tests were conducted for selected volunteers. The emission flux of DADS increased just after grilled garlic ingestion and decreased gradually thereafter. In contrast, the dermal emission flux of AMS reached a peak at 30 min after ingestion, and then gradually decreased. This peak shift suggests AMS is relatively latent in the skin organs.

Carbonaceous constituents in fine particulate matter (PM_2.5) are often associated with adverse health effects in humans. Although air filtration technology is widely used for preventing exposure to PM_2.5, the trapped PM_2.5 still has hazardous property if not treated subsequently. Thus, this study aimed to realise detoxification of PM_2.5 with a photocatalytic decomposition of carbonaceous compounds in PM_2.5 samples collected on a quartz fibre filter coated with titanium dioxide (TiO₂). The mass of PM_2.5 gradually decreased with time during the UV irradiation with a significant release of carbon dioxide (CO₂) as a product. The analysis of organic carbon (OC) and elemental carbon (EC) using a thermal/optical carbon analyser following the IMPROVE protocol showed that carbonaceous constituents such as OC1, OC2, OC3, OC4, and EC1 fractions were successfully decomposed by UV-irradiated TiO₂, whereas EC2 and EC4 fractions were inert to the photocatalysis. However, a majority of the carbon content, approximately 92% of the total carbon, was reduced by the proposed method. This shows that the photon-induced TiO₂ potentially reduces the hazardous effects of PM_2.5.