Odour and human health

What is odour?

Odour is the result of the perception of smell that occurs when chemical compounds in the air are detected by our olfactory (smell-perceiving) system. While some odours are pleasant, others can be offensive, annoying, or even harmful to human health.

Industrial activities, waste management facilities, agricultural operations, and various commercial processes can generate nuisance odours that may affect nearby communities.

The science of odour

How we detect odours

The human olfactory system is remarkably sensitive, capable of detecting thousands of different chemical compounds at very low levels in the environment. People's sensitivity to odours varies significantly due to genetic factors, age, health status, and previous exposure.  How smells are perceived can vary among individuals, a smell may be pleasant to one person and unpleasant to another - what one person finds mildly annoying, another may find intolerable.

Odour characteristics

Odours are typically characterised by several factors:

  • Intensity: How strong the odour appears to be
  • Quality: The descriptive nature of the odour (sweet, pungent, rotten, etc.)
  • Hedonic tone: Whether the odour is perceived as pleasant or unpleasant
  • Duration: How long the odour persists
  • Frequency: How often the odour occurs

Health effects of unpleasant odours

While most nuisance odours at typical exposure levels are not directly toxic, they may still affect your health and how you feel. Depending on the level of sensitivity and pre-existing health conditions, individuals can experience discomfort in the respiratory, nervous and gastrointestinal systems as well as impacts on psychological health and wellbeing.

Respiratory symptoms could include throat, nose and eyes irritation, coughing and sneezing, breathing difficulty, and exacerbation of asthma symptoms.

Common neurological effects may include headaches, dizziness, fatigue, and difficulty concentrating (‘brain fog’). Exposure to persistent and unpleasant odours can cause stress, anxiety, and sleep disruption.

Gastrointestinal reactions may include nausea, loss of appetite and general digestive discomfort. 

Individuals and communities may choose to avoid outdoor activities, which may lead to social isolation and reduced quality of life.

In some instances, in hot weather, people may find themselves choosing between heat and odour: choosing not to cool their homes and enduring excessive heat versus using their evaporative cooling system and enduring offensive odour inside. Note: excessive heat is a significant health risk, and it is important to take protective measures in hot weather. See SA Health Healthy in the heat.

Vulnerable populations

Certain groups may be more susceptible to the health effects of odours. These include children and elderly individuals, people with pre-existing respiratory and neurological conditions (asthma, COPD (chronic obstructive pulmonary disease), pregnant women.

Potential industrial odour sources

Wastewater treatment plants

  • Common odorous compounds include hydrogen sulphide, ammonia, and organic acids.

Food processing facilities

  • Odours from meat processing, rendering plants, and food manufacturing can contain various organic compounds.

Chemical and petrochemical industries

  • May release volatile organic compounds (VOCs).

Composting and waste facilities

  • Generate odours from decomposing organic matter, including ammonia, hydrogen sulphide, and various organic acids.

Agricultural operations

  • Intensive livestock operations and fertiliser applications can produce ammonia and other compounds.

Activities that disturb odorous contaminants at historically contaminated locations

  • Contaminated sites may harbor a variety of odorous compounds that can be released during remediation activities.
  • Depending on the nature of the original contaminating activities, these can include:
    • volatile organic compounds (VOCs),
    • semi volatile organic compounds, such as naphthalene and other polycyclic aromatic hydrocarbons (PAHs),
    • other odorous contaminants.

Odour regulation

Industrial activities must ensure odour emissions are managed appropriately at the source.

In Australia, odour regulation is primarily managed at the state and local governments level through several mechanisms. The approach typically includes:

  • licensing and approval processes for odour-generating activities
  • odour impact assessments for new developments
  • complaint investigation procedures
  • enforcement actions for non-compliance.

Local government regulates local odour issues using Local Nuisance and Litter Control Act 2016 as well as planning and development processes.

In matters outside of the local council’s jurisdiction, the Environment Protection Authority (EPA) regulates odour management through legislation, licensing and approvals and incident investigation processes.

What you can do

Practical steps that can be taken during an odour event include:

  • go indoors and close windows and doors if the smell is coming from outside
  • move upwind of the odour if it is safe to do so
  • reduce time spent outdoors until the odour eases, which may occur when the wind changes direction
  • if the source is known, contact the operator directly, as they may be able to take immediate steps to mitigate the odour impacts.

If you're experiencing odour issues

  • Document the problem: Record dates, times, weather conditions, and describe the odour. You may want to use the odour diary on EPA website.
  • Contact your local council or the EPA.
  • Seek medical advice: If experiencing health symptoms, consult your GP
  • Stay informed: Learn about planned industrial developments in your area

For industry and operators

  • Implement best practice: Use proven odour control technologies and management practices
  • Regular monitoring: Conduct routine odour assessments and community liaison
  • Respond promptly: Address community concerns and complaints quickly
  • Continuous improvement: Regularly review and upgrade odour management systems

Contacts

Health information 

Local councils

You can find contact information for your local council here: https://www.localcouncils.sa.gov.au/get-involved/find-your-council

EPA South Australia 

EPA South Australia

Disclaimer 

This information is for general guidance only and does not replace professional medical, legal, or technical advice. If you have specific health concerns, safety questions, or require expert assessment of contamination issues, please consult appropriate professionals.