Currently, power generation in China is dominated by thermal power, wind power, nuclear power, and hydropower enterprises. The power source mainly comes from thermal power generation. The occupational hazards in thermal power station are noise, high temperature, power frequency electric fields, dust, and chemical toxins and so on, with noise and dust (silica and coal dust) being the primary factors. The occupational hazards in wind power station are noise, power frequency electric fields, high temperature, low temperature, and chemical toxins (sulfur hexafluoride, toluene, styrene, etc.), with noise and power frequency electric fields being the major concerns. The occupational radiation hazards in nuclear power station are gamma rays, beta rays, X-rays, neutrons, alpha rays, and radioactive aerosols. There is special attention in radiation protection but not enough protection in non-radioactive hazards such as noise, high temperature, and ammonia. The occupational hazards in hydropower station are noise, power frequency electric fields, vibration, radon and its de-composites, and chemical toxins, with noise and power frequency electric fields being the primary hazards. Different categories of power generation enterprises should identify key hazards and work site for occupational disease prevention and control based on the features of occupational hazards. Improving occupational health management and protection levels are essential measures.

Corresponding author:PAN Cong-qing,E-mail:cq.pan@163.com Objective The prevalence of diabetic foot was 2.3% for out-patients and 8.6% (208/2428) for in-patients with amputation rate of 17.3% in our hospital from May 1997 to Dec 2000, more often seen on right than left extremity and in patients over 50 years old than in the younger.