Machines For Finishing Banners Machines For Finishing Banners,Welding Shop Banner,Banner Edge Welder,Banner Spot Welder NINGBO ZONGLAN MECHANICAL AND ELECTRICAL EQUIPMENT MANUFACTURE CO., LTD , https://www.zonglaneyelet.com
In the United States, a strange phenomenon has been observed: trees along the roadside have mysteriously died. Initially, people suspected that car exhaust was to blame. However, after thorough research, it was discovered that the real cause was the vibrations from passing vehicles. These vibrations disrupted the connection between tree roots and soil, ultimately leading to their death. This shows how even subtle vibrations can be harmful to plants—so what about humans?
Life in the modern world is filled with constant vibrations. City subways, buses, and industrial machinery all produce different levels of vibration. These movements are not just annoying—they can be dangerous. Vibration is now recognized as a major form of pollution in industrialized societies. Scientists have found that prolonged exposure to certain types of vibrations can lead to serious health issues.
Studies have shown that the human body reacts differently to various vibration frequencies. Experiments have demonstrated that when a person sits on a vibrating chair and the frequency gradually increases, their physical responses change. At frequencies below 1 Hz, people mainly feel head movement, and after a while, they may experience muscle pain. Between 1-2 Hz, drowsiness becomes more common. At 3-4 Hz, the waist and chest start to vibrate, while at 5-8 Hz, discomfort peaks, affecting breathing and speech. As the frequency rises further, sensations shift to the face, neck, and eyes, and vision may become impaired. Above 30 Hz, these effects tend to diminish.
Why do we react differently to varying frequencies? The human body itself contains many natural "vibrating systems." When an external vibration matches the body's own frequency, resonance occurs, amplifying the effect. The most sensitive range for human response is 5-8 Hz, followed by 10-12 Hz, which affects the thoracic and lumbar regions. Other organs also respond differently—hands are most sensitive to 18-50 Hz, the head to 2-30 Hz and 500-1000 Hz, and the nervous system to 250 Hz. This explains why visual disturbances occur most at 18-50 Hz, hand function is most affected at 30-40 Hz, and speech problems appear at 6-8 Hz.
So, how much vibration can humans tolerate? Generally, vibrations below 20 Hz become noticeable when the acceleration reaches 0.01g (1g equals Earth’s gravity). At 0.05g, people begin to feel comfortable, but above 0.3g, balance is disrupted, leading to dizziness, fatigue, and mood changes. Prolonged exposure can affect the nervous, cardiovascular, and motor systems.
To prevent vibration-related harm, it's essential to reduce mechanical vibrations or use isolation devices. If working in a high-vibration environment, using cushions or securing the body with straps can help. The best solution, however, is to avoid areas with excessive vibration whenever possible.
China Labor Insurance Network