국내에서 양식되고 있는 김의 대표적인 품종으로는 참김(P. tenera), 방사무늬김(P. yezoensis), 모무늬돌김(P. seriata) 및 잇바디돌김(P. dentata) 등이 있는데, 이들 중 참김과 방사무 늬김이 예로부터 양식되어져 온 주요 품종으로 엽체가 얇고 부 드러운 것이 특징이며 국내 생산량의 약 70%를 차지하고 있다 (Hwang et al., 2005). 시중에 유통되는 마른 김은 100% 돌김 이나 일반적으로 방사무늬김과 돌김이 혼합되어 있는 형태로 양식지역마다 현지 사정에 따라 몇 품종들을 섞어서 마른 김으 Article history;To investigate heavy metals (Hg, Pb and Cd) and their potential health risks in commercial dried laver (Porphyra sp.), we collected 45 samples from the major production areas on the western and southern coasts of Korea (Hwaseong, Seocheon, Gunsan, Muan, Shinan, Jindo, Haenam, Wando, Jangheung, Goheung and Busan). The Hg, Pb and Cd concentrations were measured using inductively coupled plasma spectrometry (ICP-MS) or a mercury analyzer. The average Hg, Pb and Cd concentrations in the dried laver were 0.006±0.0017, 0.196±0.0614 and 0.894±0.4882 mg/kg, respectively. Based on the 2007 Korean Public Nutrition Report, these levels are 0.02, 0.11 and 2.47% of the provisional tolerable weekly intake (PTWI) for Hg, Pb and Cd, respectively, established by the FAO/WHO. The hazard quotient (HQ) determined from the ratio of exposure and safe levels were less than 1.0. Therefore, the levels of overall exposure to Hg, Pb and Cd for dried laver were below the recommended JECFA (Joint FAO/WHO Expert Committee on Food Additives) levels, which indicate safe levels for public health.

In Korea, oysters are used as an ingredient of Kimchi (Korean pickled cabbage) in early winter. Although viral contamination of oysters, including contamination by norovirus, can provoke gastroenteric illness, little is known of the epidemiological relationship to outbreaks. We postulated that Kimchi ripening can reduce the infectivity of norovirus, in order to test this hypothesis, we carried out a model experiment. Since norovirus is currently regarded as non-culturable, feline calicivirus (FCV) was used as a surrogate to examine the activation of norovirus with Kimchi ripening. In commercial well-prepared Kimchi, the infectivity (TCID 50 ) of FCV decreased by 2 log every 12 hours and reached the limit of detection after 48 hours during over-aging at 25 ℃ . During storage at 4 ℃ , the infectivity (TCID 50 ) of FCV decreased slowly and reached 5.00 TCID 50 after 48 hours. The low pH appears to affect the infectivity of FCV directly via organic acids produced by ripening during over-aging and storage. In neutralized lab-prepared Kimchi (pH 7.0), the infectivity (TCID 50 ) of FCV also decreased and reached the limit of detection after 72 hours at 4 ℃ . This indicates that there are substances beside organic acids in Kimchi that originate from the raw materials and are produced during ripening. Among the raw materials, salt-fermented anchovies and garlic showed high direct antiviral activity. The main factor decreasing the infectivity of FCV in Kimchi was the high acidity caused by organic acids, regardless of the type, produced by ripening. Furthermore, unknown secondary products of microorganisms associated with Kimchi ripening and antiviral materials originating from raw material might contribute to the decreased infectivity of FCV, the surrogate of norovirus.