Environmental Noise Guidelines for the European Region
About this book
The WHO Environmental Noise Guidelines for the European Region (2018) represents a major update to the evidence-based framework for protecting human health from noise pollution, published by the World Health Organization Regional Office for Europe. Developed through a systematic review process examining thousands of epidemiological studies, the guidelines establish recommended noise exposure levels for four primary outdoor environmental noise sources: road traffic, railway, aircraft, and wind turbines. The guidelines adopt a health-effects-based approach rather than a purely acoustic approach.
They draw on a comprehensive systematic review of the evidence linking specific noise levels to defined health outcomes, including cardiovascular disease (ischaemic heart disease and hypertension), sleep disturbance (measured through actigraphy and self-reporting), cognitive impairment in children (reading comprehension, language acquisition, and sustained attention in school environments), tinnitus, and annoyance (the most widely studied endpoint, assessed using validated questionnaire instruments). For road traffic noise — the dominant noise source affecting the largest population in Europe — the WHO guidelines recommend that average levels (Lden) should not exceed 53 dB outdoors and that night-time noise (Lnight) should not exceed 45 dB, with a strong recommendation for levels as low as 45 dB Lden when feasible based on the evidence for cardiovascular effects below this threshold. These recommended values are substantially lower than the EU Environmental Noise Directive (END) action planning thresholds and have prompted debate about the feasibility of compliance.
For aircraft noise, the guidelines recommend Lden below 45 dB and Lnight below 40 dB, reflecting the evidence of stronger annoyance and sleep disruption per unit of noise for aircraft compared to road traffic. For railway noise, slightly higher limits (Lden 54 dB, Lnight 44 dB) are recommended based on the so-called rail bonus — the documented tendency for railway noise to cause less annoyance than equivalent road noise levels, though the guidelines note this bonus is weaker than previously assumed. For wind turbines, the evidence base is more limited but supports a recommended Lden of 45 dB to avoid annoyance.
The guidelines also address the particular sensitivity of children's learning environments to noise, recommending indoor noise levels in school classrooms not exceeding 35 dB LAeq to avoid cognitive interference. Practical implementation chapters address noise barriers, façade insulation requirements, quiet façades, urban planning setbacks, night flight restrictions, and the interaction with air quality policy through street canyon ventilation design. The document is a foundational reference for European urban planners, acoustic engineers, public health authorities, and transport infrastructure developers.