How claims on this site are sourced.

Source hierarchy

1. Institutional public-health guidance — World Health Organization Europe noise fact sheet and night-noise guideline; CDC and EPA materials where applicable; OSHA and NIOSH for occupational standards.
2. Peer-reviewed clinical and acoustical literature — for cardiovascular, sleep-architecture, cognitive, and infrasound claims. Sourced via the published reviews and meta-analyses summarized on each page; primary citations are listed on Sources.
3. Primary regulatory text — for statements about specific bans (California AB 1346, D.C. Law 22-281, municipal ordinances), the underlying bill or ordinance text is the canonical source.
4. Trade and policy reporting — for current-state implementation notes (CARB enforcement updates, municipal-ban map maintenance), reputable advocacy organizations and trade press are used as a starting point and cross-checked against primary documents.

Documented vs. provisional

The site is honest about which claims rest on a firm published base and which rest on more provisional ground. Pages flag this where it applies. The split, in summary:

Documented (peer-reviewed or institutional)

• WHO night-noise guideline of less than 40 dB(A) outside bedrooms; less than 30 dB(A) in bedrooms
• Approximately 40% of the EU population exposed to road-traffic noise above 55 dB(A); more than 30% above 55 dB(A) at night
• Cardiovascular effects of chronic noise — elevated blood pressure, heart-attack risk, stroke risk
• Aircraft-noise cognitive impairment in children
• Cortisol–melatonin antagonism
• California AB 1346 (2021) phasing out gas-powered lawn equipment
• OSHA permissible exposure limit of 90 dB(A) TWA; NIOSH recommended exposure limit of 85 dB(A) TWA
• Vic Tandy infrasound research (Journal of the Society for Psychical Research, 1998) on 18 Hz standing waves and physiological / perceptual effects

Provisional or contested

• Specific magnitudes of cardiovascular damage attributable to gas-powered backpack blowers vs. other residential noise sources — the dose-and-modulation profiles are not yet measured at the granularity that would tighten this further
• Field prevalence of pulsed-white-noise sources in consumer residential devices — under-studied
• The full magnitude of EMF–melatonin interaction with noise-induced cortisol
• The dose-response curve for sleep-architecture fragmentation in habituated subjects who report not noticing the noise — the direction is well-supported, the curve less so

What is editorially excluded

• Naming individuals. The site does not identify specific landscape workers, property owners, residents, or contractors.
• Diagnostic claims about specific people. Symptoms are described in general terms, not pinned to identified persons.
• Medical, legal, or policy advice for specific situations. Specific situations need professionals.
• User-generated content. No comment system, no forum, no submission form.
• Speculative claims about intent. The site argues that the equipment functions in a particular way regardless of operator intent; it does not impute malicious intent to operators.

Corrections

If a claim is wrong or has become outdated — a regulation has changed, a study has been retracted, a citation is mis-attributed — the page is updated promptly. Email at /sources/.