Health Effects of Long-term Tuna Diet in Cats: I. On the dose-response relationship between the amount of tuna consumed and the numerical aberration of lymphocyte chromosome

A positive correlation between the amount of mercury contaminated tuna intake and the amount of mercury in the human scalp hair has been observed in both the epidemiological and the experimental studies, and also the evidence showed the positive dose-response relationship between the amount of intake of methyl mercury incorporated in mercury contaminated fishes and the concentration of mercury in blood samples. However, other problem for health effects of long-term tuna diet has not been obvious. In order to determine the health effects of long-term tuna diet, the cats fed with tuna meat in this experiment for more than two years have been observed for the accumulation of mercury in vaious organs and related health effects including the numerical aberration of lymphocyte chromosome. The experimental cats were divided into two groups according to the mercury levels in the tuna. The first group were given tuna of mercury level 0.665ppm, and the second group were given tuna of mercury level 0.995ppm. A comparison was made on the concentration of mercury in the biological specimens between control and experimental groups, and the mercury levels in the experimental groups were obviously higher than those in the control group. Also, the cats in the second group showed more frequent and significant symptoms than those of the first group. The percentage frequences of the numerical aberration of lymphocyte chromosome in the control group, the first group and the second group were 3.62, 29.3 and 62.5%, respectively. The difference in each group was statistically significant.