||Since the species emitted from restaurants contain heptaldehyde, octylaldehyde, nonanaldehyde and decylaldehyde, high-temperature cooking processes and indoor cleaning activities tend to contribute to formaldehyde. However, long-time exposure to carbonyls has been known to have a significant influence on human lungs and induce cancer as well. This study was targeted at the dining areas and cooking areas of the restaurant in eight types in Kaohsiung Area—namely, Chinese buffet, Chinese vegetarian, Chinese hot pot, Japanese barbecue, Western fast food, Chinese-Western mixed style, Western breakfast and Chinese stir-frying, to probe into the potential existence of carbonyls as well as their correlation, and assess its health risk. The result of this study suggest that the most common carbonyls in dining areas are formaldehyde (0.52–30.12 ppb), Acetaldehyde (0.030–7.51 ppb) and acetone(0.25–3.19 ppb), while hexaldehyde (0.45–8.52 ppb), heptaldehyde (0.16–3.41 ppb), Octylaldehyde(0.20–6.15 ppb) and nonanaldehyde (0.79–22.15 ppb) are largely found in cooking areas.|
Since food cooked by oil can turn out C5-C10 carbonyls, the dining areas of Japanese barbecue restaurants were proved to have the highest carbonyl concentration (45.06 ppb), whereas the cooking areas of the Chinese-Western complex restaruants had the highest carbonyl concentration (45.48 ppb). The result of the carbonyl concentration in exhaust pipes in relation with the odor threshold shown that the odor is attributed to those high carbon-containing species (C6 – C9). Among them, the octylaldehyde in Western fast-food restaurants can reach up to 1298.33 times as much as the odor threshold.
What’s more, as far as the risk assessment of cancer-inducing and non-cancer-inducing factors are concerned, the cancer risk in the indoor dining areas is projected at between 1.69×10-8 and 1.31×10-6, those in Chinese hot pot restaurants being the highest (1.31×10-6). The hazard index is at between 0.05 and 18.81, Chinese vegetarian restaruants being the highest (18.81). On ther other hand, the cancer risk of the cooking areas is at between 4.35×10-8 and 7.82×10-7, with Chinese vegetarian restaurants being the highest (7.82×10-7), while the hazard index is at between 0.16 and 6.02, with Western breakfast eateris being the highest (6.02).