Effects Oflow Incident Levels of Laser Irradiation and Other Environmentalfactors on the Production Capability of Reactive Oxygen Species from Human Neutrophils

In order to evaluate the relationship between reactive oxygen species (ROS) production from human neutrophils and the health of the organism, we developed a new technique and apparatus to measure ROS, and studied the relationship between ROS production and many kinds of environmental factors, such as the circadian rhythm, various degrees of exercise loading and training, diet, alcohol, smoking, and other environmental factors. ROS production and serum opsonic activity did not significantly change at levels of up to 50-60% of VO₂max, as advocated by the Japanese Ministry of Health, Labour and Welfare, but in the case of exercise overloading tomore than 65%VO2max, ROS production increased. On the other hand, when neutrophils were exposed to environmental factors, e.g., ethanol, minerals, interferon, laser, ultraviolet light and so on, at a low density, ROS production from neutrophils was only slightly enhanced. However, when neutrophils were exposed to the same environmental factors at an excessive density, ROS production significantly decreased. Given that small increases in ROS production from neutrophils are beneficial to the organism, as many researchers have reported, ROS production at low density exposure to environmental factors may increase the autoimmunocompetency of the organism, in other words, it is good for the health. Furthermore, ROS production and serum opsonic activity showed an inverse relationshipinmany kinds of environment, indicatingamu-tual compensatory mechanism to maintain the homeostasis of the autoimmune system.