Peculiarities of monitoring for infrasound pollution of residential areas located in proximity to highways

Introduction. Procedural provision of studies on monitoring for infrasound pollution of residential areas located in proximity to highways is the issue of the consideration in this article. The fact of the absence of a standardized procedure for carrying out large-scale studies of the infrasound range of the sound pressure in residential areas is reported. A brief review of regulatory documents currently used by experts of accredited laboratories, hygiene and epidemiology centers to solve sanitary problems of infrasound range acoustics, is given. 

Material and Methods. As a rule, experts use techniques for a hearing range of noise measurements and procedures specified by device service instructions which result in significant inconsistencies of research findings. Determination of parameters affecting the accuracy of research findings carried out with the help of routine devices available in hygiene and epidemiology centers was the objective of infrasound measurements presented here. 

Results. Effect of wind flows, study duration and monitoring location point were found to be the major parameters affecting the accuracy of research findings. Data on wind load on Saint-Petersburg territory is reported. Territories in the immediate proximity to the “West Speed Diameter” (WSD) highway, Ring motorway and Sinopskaya embankment being potential infrasound sources, were chosen for experimental studies. Such choice was caused by the heavy freight and passenger car traffic characterized by relatively permanent intensity. 

Discussion. Measurement series at various wind loads and of different durations were done. Measurement points were chosen in free field and in the vicinity of echoing areas. Measurement data were assessed taking into account expanded uncertainty, at 95% confidence level. It was found that reliable measurement results in infrasound frequency range can be obtained on the territory at wind velocity not exceeding 1 m/sec, during measurements in the free sound field with duration over 20 minutes. Given wind load conditions can be realized in St.-Petersburg for several days a month.