Health effects and noise exposure among flight-line mainteners

A Portuguese researcher group has reported long term effects on the internal organs through prolonged exposure to LFN, defined as noise < 500 Hz and > 90 dB (Castelo Branco & Alves-Pereira 2004), and have grouped the changes and symptoms in a syndrome called Vibro-Acoustic-Disease (VAD). Their main finding is proliferation of connective tissue, i.e. thickening of the pericardium, but changes of the respiratory and gastric epithelium are also reported. Late onset epilepsia and endocrine or autoimmune disorders have also been described as possible expressions of VAD. However, their research results have been questioned (von Gierke & Mohler, 2002).