Gastrointestinal problems in vibroacoustic disease

INTRODUTION: The clinical stages of vibroacoustic disease (VAD), as advanced in 1998 for aircraft technicians, show that gastrointestinal (GI) complaints appear within the first 3 years of occupational exposure to low frequency noise (LFN, <500 Hz, including infrasound). Within 12 years of LFN exposure, gastritis can develop, and further exposure can induce digestive mucoSa hemorrhages, duodenal ulcers and colitis. In the vast majority of these cases, symptoms diSappeared when the individual was removed from the LFN-rich environment, either by vacation or job change, but re-appeared when exposed again to LFN. This report expands on what is known to date on GI problems associated with LFN exposure. In 100% of the aircraft technicians with more than 15 years of occupational activity, with or without GI tract symptoms, all had Helicobacter pylori infections. ANIMAL MODEL: The LM and SEM study of the LFN-exposed Wistar rat model of VAD showed gastric and duodenal erosions, epithelial cell death and duodenal microvilli destruction. CLINICAL REPORTS: Two patients presented metastatic tuberculosis (TB) of the colon. All malignant cases of the GI tract were poorly differentiated adenocarcinomas located in the stomach and colon. More recently, endoscopic studies demonstrated that VAD patients have similar mucoSa erosions as seen in LFN-exposed animal models. DISCUSSION: GI tract pathology is present in VAD patients and in LFN-exposed animals. LFN seems to affect hollow organs, such as the respiratory system, hence it is not entirely surprising to see GI tract pathology in VAD patients. Not much attention is paid to GI complaints in LFN-exposed individuals, oftentimes because they are thought to be associated with a generalized stress syndrome. Large-scale and in-depth studies investigating the effects of acoustic phenomena on the GI tract are still lacking.