ORDINARY MEETING MINUTES DATED 18 SEPTEMBER 2025 · 2025-09-18 Ordinary Meeting Minutes

ORDINARY MEETING MINUTES                                                    18 SEPTEMBER 2025


     (RCS) is a known occupational hazard in industries involving cutting, crushing or drilling of
     silica-containing materials. However, the context of road dust from unsealed surfaces,
     particularly those maintained using natural gravel and recycled asphalt, differs significantly
     from high-risk occupational environments where RCS may be present. Noosa Council
     maintain their unsealed road networks using natural gravel blends and recycled asphalt
     pavement (RAP). These materials are selected in accordance with:
      Queensland Department of Transport and Main Roads MRTS05 – Unbound Pavements;
          and
      Austroads Guide to Pavement Technology Part 6: Unsealed Pavements.
    These standards ensure that materials meet performance criteria such as California Bearing
    Ratio (CBR), shrinkage product and grading coefficient, which indirectly influence dust
    generation and stability.
    In terms of health risk exposure:
     Unsealed roads in these regions typically carry low traffic volumes (30–500 vehicles/day).
     Dust exposure is intermittent, outdoor and dispersed, significantly reducing concentration
         compared to enclosed occupational settings.
     A New Zealand Transport Agency study found that while PM₁₀ dust from unsealed roads
         can be present, respirable silica levels were generally low and not linked to adverse health
         outcomes in ambient settings.
     NIOSH evaluations of dirt road maintenance found no erionite and only occasional silica
         exceedances, primarily in active roadwork zones, not general public exposure.
     The Workplace Exposure Standard (WES) for RCS in Australia is 0.05 mg/m³ (8-hour
         TWA). Ambient exposure from unsealed roads is not known to exceed this threshold in
         SE Queensland.
    Based on current material usage, maintenance practices and environmental exposure
    conditions, there is minimal to no health risk from silica dust generated by unsealed gravel
    roads in the Noosa Council region. There is no confirmed evidence of harmful silica dust
    concentrations in these areas, and no recorded public health impacts attributable to road dust.
    The use of natural gravel and recycled asphalt, combined with routine grading and dust
    suppression, ensures compliance with engineering and environmental standards. In terms of
    testing its workforce, Noosa Council test the workers that are exposed to Respirable
    Crystalline Silica (RCS) such as concrete cutting, drilling and crushing works which is
    approximately 50 workers. Crews working on our unsealed roads such as grader crews and
    plant crews are not tested due to low risk profile.
    In terms of dust management for the community, Council’s current dust mitigation strategies
    include:
     Routine grading and re-sheeting based on traffic volume and environmental conditions;
     Use of impervious gravel blends (such as recycled road profiles) where possible and
         available to reduce water ingress and dust lift-off; and
     Community education sheets recommending various practices including vegetative
         screening and reduce dust impacts near residences.
    Council has explored the use of dust suppressants as noted in the question and can advise
    as follows:
     Dust suppression chemical treatments can be used to treat problematic areas and are
        commonly used in intensive industrial and mining applications;
     The treatment is usually only effective for approximately 3 months and can make the road
        slippery when it rains as they are commonly hydrophobic and cause water to pond on the
        surface causing possible safety issues;
     These chemicals are powerful and would need to be applied with great prudence as could
        have adverse environmental implications if overused particularly pertinent in
        environmentally sensitive areas of Noosa Shire;