Environmental Health
Environmental health encompasses the assessment, correction, and prevention of environmental factors that can adversely affect human health, including air and water quality, housing, food safety, radiation, climate change, and occupational exposures.
Key Facts
Air pollution is estimated to cause 28,000-36,000 premature deaths/year in the UK; PM2.5 is the most harmful pollutant Clean Air Act 1956 (following Great Smog of London 1952) was landmark UK environmental health legislation Water quality is regulated under the Water Supply (Water Quality) Regulations; E. coli and Cryptosporidium are key pathogens monitored Housing conditions (damp, cold, overcrowding) are major determinants of health; estimated to cost the NHS £1.4 billion/year Climate change is recognised by WHO as the greatest health threat of the 21st century Radon: naturally occurring radioactive gas; second leading cause of lung cancer after smoking; high levels in parts of Southwest England COMEAP (Committee on the Medical Effects of Air Pollutants) advises UK government on air pollution health effects Environmental Health Officers (EHOs) enforce regulations on food safety, housing, noise, pollution at local authority level
Overview
Key Facts
Environmental health is a broad discipline addressing the interaction between human health and the physical, chemical, and biological environment. Environmental factors are estimated to contribute to 23% of global disease burden.
Key Environmental Health Domains
- Air quality: outdoor (particulate matter, NO₂, ozone) and indoor (radon, CO, mould spores)
- Water and sanitation: drinking water quality, sewage treatment, waterborne disease
- Food safety: food hygiene, food-borne illness prevention, food standards
- Housing: damp, cold, overcrowding, housing fitness standards
- Occupational health: workplace hazards, occupational diseases
- Radiation: ionising (radon, medical) and non-ionising (UV, EMF)
- Noise: environmental and occupational noise exposure
- Climate change: extreme weather, vector-borne disease, food security, mental health
- Waste management: hazardous waste, landfill, pollution
Regulatory Framework
- Environmental Protection Act 1990
- Clean Air Acts (1956, 1968, 1993)
- Food Safety Act 1990 and EU-derived food hygiene regulations
- Housing Act 2004 (Housing Health and Safety Rating System)
- Control of Substances Hazardous to Health (COSHH) Regulations 2002
- Environment Act 2021 (air quality targets)
Clinical Presentation
Health Effects of Environmental Exposures
Air pollution:
- Exacerbation of asthma and COPD
- Increased cardiovascular events (MI, stroke)
- Lung cancer (PM2.5 exposure)
- Low birth weight and preterm birth
- Cognitive decline in elderly
Water contamination:
- Gastroenteritis (Cryptosporidium, E. coli, norovirus)
- Chemical contamination (lead, fluoride, nitrates)
Housing:
- Damp and mould: respiratory disease, asthma exacerbation (especially children)
- Cold homes: excess winter deaths (approximately 25,000/year in England)
- Overcrowding: infectious disease transmission (TB, COVID-19)
Climate change:
- Heat-related illness and mortality (heatwaves)
- Flooding: physical injury, mental health impact, waterborne disease
- Changing patterns of vector-borne disease (tick-borne encephalitis, Lyme disease)
- Food insecurity
- Mental health: eco-anxiety, displacement
Red Flags for Environmental Health Concerns
- Cluster of unexplained illness in geographic area
- Respiratory symptoms in multiple occupants of same building (sick building syndrome)
- Recurrent childhood asthma exacerbations with visible mould in home
- Carbon monoxide poisoning (headache, nausea, confusion — from faulty gas appliances)
Differential Diagnosis
| Environmental Exposure | Health Effect | Investigation |
|---|---|---|
| PM2.5 air pollution | Asthma, COPD exacerbation, CVD | Air quality monitoring data |
| Radon | Lung cancer | Radon testing in home |
| Lead (water/paint) | Developmental delay (children), anaemia | Blood lead level |
| Damp/mould | Asthma, allergic bronchopulmonary aspergillosis | Housing inspection, IgE |
| Carbon monoxide | Headache, confusion, collapse, death | CO detector, carboxyhaemoglobin |
| Asbestos | Mesothelioma, asbestosis, lung cancer | Occupational history, CXR, CT |
Diagnosis / Investigation
Environmental Assessment
- Environmental health officer inspection (housing, food premises, workplaces)
- Air quality monitoring (DEFRA network)
- Water quality testing (local water company, Environment Agency)
- Radon testing kits (PHE/UKHSA)
- Noise monitoring
- Occupational hygiene assessment
Clinical Investigation
- Carboxyhaemoglobin: CO poisoning
- Blood lead level: lead exposure
- Urinary arsenic, mercury: heavy metal exposure
- Spirometry: occupational lung disease
- CXR/CT: asbestosis, mesothelioma
- Patch testing: occupational contact dermatitis
Management
Interventions
Air quality:
- Clean air zones in cities (ULEZ in London)
- Promotion of active travel (cycling, walking)
- Advice to vulnerable patients on high pollution days (stay indoors, avoid exertion)
- Environment Act 2021 targets for PM2.5
Housing:
- HHSRS (Housing Health and Safety Rating System) assessment by local authority
- Landlord obligations for damp/mould remediation
- Warm Home Discount and Winter Fuel Payment schemes
- Decent Homes Standard
Food safety:
- Food hygiene ratings (Scores on the Doors)
- HACCP (Hazard Analysis and Critical Control Points) in food businesses
- EHO inspections and enforcement
Climate adaptation:
- Heatwave plans (NHS)
- Flood resilience planning
- Green infrastructure (urban green spaces, trees)
GP Role
- Recognise environmental contributions to patient illness
- Ask about housing conditions, workplace exposures
- Refer to environmental health for housing concerns
- Report suspected occupational diseases (RIDDOR)
- Advocate for healthy environments
- Advise vulnerable patients during extreme weather events
Prognosis
- Air pollution reduction has shown measurable health benefits (London ULEZ: 13% reduction in NO₂)
- Radon remediation reduces lung cancer risk
- Housing improvements reduce respiratory disease and improve mental health
- Climate change will increasingly impact health in the UK (heatwaves, flooding, infectious disease patterns)
- Environmental health interventions are generally highly cost-effective
- The Built Environment contributes significantly to physical activity levels and obesity
Other Relevant Information
Air Quality Index (DAQI)
| Index | Banding | Health Advice (At-Risk Groups) |
|---|---|---|
| 1-3 | Low | Enjoy usual activities |
| 4-6 | Moderate | Consider reducing strenuous activity if symptoms |
| 7-9 | High | Reduce strenuous activity |
| 10 | Very High | Avoid strenuous activity |
Key Environmental Health Legislation
| Legislation | Focus |
|---|---|
| Clean Air Act 1993 | Air pollution control |
| Environment Act 2021 | PM2.5 targets, nature recovery |
| Food Safety Act 1990 | Food safety standards |
| Housing Act 2004 | HHSRS, housing standards |
| COSHH 2002 | Workplace chemical hazards |
| Environmental Protection Act 1990 | Waste, contaminated land, statutory nuisance |