OCC/Welfare/TBT-OCC-037

Bioaerosol Exposure

Occupational Health › Welfare › Bioaerosol Exposure

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Bioaerosols are airborne particles containing bacteria, fungi, viruses, and endotoxins from biological sources.
They are generated on construction sites during work involving sewage, composting, demolition, and contaminated land.
Wastewater treatment works produce bioaerosols from aeration lanes, inlet works, sludge handling, and screening.
COSHH 2002 requires employers to assess and control exposure to biological agents including bioaerosols.
Inhalation of bioaerosols can cause respiratory illness, gastrointestinal symptoms, and flu-like reactions.
Specific organisms of concern include Legionella, E. coli, Aspergillus, and endotoxin-producing bacteria.
Workers within 100 metres downwind of bioaerosol sources may be exposed to elevated concentrations.
Immunocompromised workers face greater risk and may need additional protection or task reassignment.
There is no UK workplace exposure limit for bioaerosols, so control must follow the ALARP principle.
Health surveillance may be required for workers regularly exposed to bioaerosols on wastewater sites.

Respiratory illness	Inhaling bioaerosols causes chest infections, hypersensitivity pneumonitis, and chronic respiratory conditions over time.
Invisible hazard	Bioaerosols are invisible and odourless at harmful concentrations — you cannot detect exposure without monitoring.
WwTW specific risk	Construction workers on wastewater treatment sites face elevated bioaerosol exposure from active treatment processes nearby.

Don't

Check the COSHH assessment for bioaerosol risks before working near biological processes.
Work upwind of bioaerosol sources such as aeration lanes and screening areas where possible.
Wear the RPE specified in the risk assessment when working near bioaerosol sources.
Wash hands and face thoroughly before eating, drinking, or smoking on WwTW sites.
Use welfare facilities provided — do not eat in work areas near treatment processes.
Report any respiratory symptoms, persistent coughs, or flu-like illness to your supervisor.
Change out of contaminated work clothing before travelling home at the end of shift.
Attend health surveillance appointments when scheduled by the occupational health team.
Keep cuts and grazes covered with waterproof dressings when working near sewage.
Inform your supervisor if you are immunocompromised or taking immunosuppressant medication.

DON'T eat, drink, or smoke in work areas near sewage, sludge, or treatment processes.
DON'T work downwind of aeration lanes or open sewage processes without RPE protection.
DON'T touch your face, eyes, or mouth with contaminated gloves or unwashed hands.
DON'T use compressed air to clean contaminated clothing or equipment near process areas.
DON'T ignore flu-like symptoms after working near bioaerosol sources — report them promptly.
DON'T assume outdoor work means bioaerosol exposure is negligible — wind carries particles far.
DON'T take contaminated work clothing home in the same bag as clean personal items.
DON'T create unnecessary spray or splash when working with or near sewage liquors.
DON'T skip hand washing — biological contamination cannot be seen on apparently clean skin.
DON'T refuse health surveillance — early detection protects your long-term respiratory health.

See also: Leptospirosis (Weils Disease) Awareness | Health Surveillance Programme

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