Environmental Health Summary Year 3
Session 1: Soil and Air
Outdoor Air:

Important sources of outdoor air pollution are car emissions (chemical reaction between N
and O2 in air releasing nitrous oxide and nitrous dioxide – in presence of UV light these
react to form ozone O3 which is also irritant gas) and other burning of fossil fuels which
form aerosols and gases which are irritants of alveoli.

Pollutants build in concentration when AIR INVERSION occurs. Air inversion occurs when
on a cloudless still night, the air close to the ground becomes cold and the hot air moves
upwards as it is less dense (called convection).

Gaseous oxides of carbon – CO and CO2 which contribute to the greenhouse effect and CO
reacts with Hb to displace O2 from oxygen transport. CO absorbed by tobacco smokers.

Photochemical smog = ozone, nitrous oxide and dioxide and unburnt hydrocarbon vapour
that forms brown irritant gas from vehicles.
General advice for medical practitioner: avoid exposures (long walks on highways, outdoor
activities on peak pollution days, stop smoking, extreme temperatures (cold exacerbates asthma)).
Air Quality Environmental Monitoring: indicated by levels of NO2, O3, hyrocarbons, lead, CO, SO2
and volatile organic compounds in the air = higher levels means more likely you are breathing
POOR QUALITY AIR which can react in people with hyperactive airways and compromise lung
function.

EPA (Environmental Protection Authority): issues pollution warnings and monitors air
quality. Has air quality bulletins and forecasts for 24hours etc. measures particles in air and
levels of air pollutants. Important in things like bushfires and so people with underlying
lung conditions can monitor when they should not do outdoor activities.

Health effects of air pollutants are known about through epidemiological studies and
experimental studies.
o Epidemiological: high statistical power but many confounding factors
o Experimental: known doses recorded due to controlled level and duration of
exposure but limited statistical power.
Indoor Air: sources of indoor pollutants include tobacco smoke, smoke from wood fires, NO2 from
flame gas appliances, CO from burning oils/gas/wood, fibres (asbestos) in roofs etc.

Tobacco smoke: assoc with lung cancer, angina, asthma, resp infections, otitus media

Carbon monoxide (CO): forms strong bond with Hb creating carboxy-heamoglobin reported
as a percent (%CO-Hb). Affects such as angina at as little as 2.5%, at levels of 17% there is
diminished visual perception and loss of mental dexterity.

Volatile organic compounds (VOC): eg. Formaldehyde can cause resp irritation, reduced
stability of tears across eyes, increased polymorphs in conjunctiva, resistance to airflow in
nose and 10% reduction in FEV1 – group of symptoms referred to as SICK BUILDING
SYNDROME. Includes symptoms of eye, nose, throat irritation, headache, erythema, cough,
itch, nausea etc. It is NOT really a syndrome as the S+S from such a wide range of
pathologies.
Soil Quality:
Assessing concerns of contamination: is there evidence, what are likely contaminants, are there
significant exposure opportunities (ingestion, inhalation, dermal), are protective measures or
treatments available.
Are BIOMARKERS available – evidence of adverse affects on individuals eg. Rash.vomiting, neuro
change.
Soli intake: highest in age 1.5 to 2.5 y/o from playing.
If old industrial site is planned to used for housing government has to give permit, test soil etc.
Testing of soil of person living in house more expensive then replacing the soil itself.

EPA involved with monitoring land quality and contamination.
Session 2: Food and Water
Role of clinician in regards to water: assess and diagnose patients with water quality problems,
manage the illnesses associated with water problems, and to assist local health authorities to
investigate disease outbreaks associated with water quality issues.
 2.2millipm deaths each year due to unsafe and unsanitised water, mainly children in
developed countries.
Management of water quality  need balance between minimal chemical and microbial
contamination while still being aesthetic with taste, odour and colour.
Surface water supplies (rivers, lakes) more prone to microbial contamination then underground
supplies (bore water, springs).
Water contaminants:
 Globally: greates issue is the arsenic in water supplies in Bangladesh. Long term drinking of
this water causes skin changes, urinary tract cancer, skin cancer, peripheral neuropathy.
 Australia’s greatest water concern is that of MICROBIAL CONTAMINATION:
o Arise largely from human or animal faecal sources, can be viral/bacterial/protozoa.

enteric viruses (rotavirus, norovirus): human faeces as no animal reservoir

pathogenic bacteria (salmonella, campylobacter): humans, animals and
birds

protozoa (cryptosporidium and giardia): humans and mammals
o Microbiological parameters measured weekly and chemical assessment done
quarterly. Done by water authorities.
o Treatment of water involves:

Disinfection using chlorine. However viruses and protozoa are relatively
resistant to chlorine.

Flocculation, coagulation and sedimentation followed by FILTRATION to
remove microbial particles and chemicals.

Fluoride is added
Australian Drinking Water Guidelines (ADWG) provide framework for acceptable drinking water
quality, but this cand be flexible within communities.
Food Contamination:
Four million cases of foodborne infectious diseases occurring annually in Australia.
HACCP (Hazard Analysis and Critical Control Point) is an international standard procedure that is
used to reduce the risk of foodborne diseases. Their procedures involve:

Identifying potential hazards and control methods; identifying points in food production
where contamination can occur, establishing preventative measures, monitoring critical
points, taking corrective actions and maintaining records related to food and procedures.
Recognised food borne pathogens include:

Bacillus cereus: in rice poorly reheated,

Salmonella: meat, poultry

Campylobacter: meat, eggs, raw milk.

Protozoa (cryptosporidium) – related to water run off that contaminates fresh fruit and
vegies.
Genetically Modified Food:
Genetically Modified foods are those that contain novel DNA and/or novel protein. These food
must be labelled appropriately.
Foods that do NOT need GM labelling (even if they do have been involved in genetic modification)
are: highly refined foods, flavourings, vending foods or takeaway outlets, GM food is less then 1%
of food product.
Some GM foods may need additional labelling if there are concerns over ethics/culture or if the
food has altered characteristics (changed nutritional value, potential for allergy etc).
Basically all processes foods cannot be GM free.
Session 3: Two populations at risk from their environment (Indigenous communities)
Indigenous Community Health:
 Aboriginal life expectancy at birth is about 20 years younger then for non-Aboriginal
Australians. Three quarters of these deaths are caused by CVD, injury, resp disease, cancer
and DM (and complications). Also higher rates of ID, kidney disease, resp disease, asthma,
otitis media.
 60% of the Aboriginal population are overweight.
 Much higher rate of teenage pregnancy  brings poverty and limited education
 Highest global rate of Rheumatic fever and rheumatic HD. Also high rates of HIV, TB and
Hep B.
 Alcohol, petrol sniffing, marijuana, and suicides are huge concerns.
 Lower rates of employment, school attendance; higher rates of gaol and police custody.
Environmental determinants of health in remote communities:
1. Inadequate water supply and quality
2. Inadequate housing
3. Shortage of affordable healthy food
4. Other: crowding, no clothing/washing facilities, dogs, dust, extreme temperatures etc.
Common infectious agents in remote communities: Camplylobacter, Salmonella, Shigella,
adenovirus, Giardia, hookworm. Represent sewage leaks into water supply.
*NOTE: often in remote areas it is WATER WASHED rather than WATER BORNE  meaning that
they don’t use ENOUGH WATER rather than that the water is poor quality. Not enough water
means they don’t wash hands or food or eating surfaces etc.
Aboriginal Liason Officers: These are employed by most major hospitals to support aborigines
admitted to hospital and provide guidance on request to health professionals.
Child Safety in Play (environmental child safety issues):
 Aged <5: head, face and scalp injuries most common
 Aged 5-14: injuries to upper limb most common
 Most common injury mechanism is falls, often on playgrounds at home, parks or schools.
Injury from playground equipment associated with poor design, poor maintenance, lack of
adult supervision etc.
Patterns of injury change as a child develops and does different activities and goes through stages
of neural and muscular development.
Session 4: Climate and Radiation
Global Climate Change:
Clinicians role involves recognising medical conditions that may become more preva
lent due to global warming and advise patients of preventative strategies for these conditions.
Chemical changes to the atmosphere:
 Convection = upward floating of a mass of air that is warmer (and therefore less dense)
then it’s surroundings.
 Global temperature from infra-red radiation (from sun) and a tiny portion from the earth;s
molten surface. The earths surface emits infra-red heat radiation  TERRESTIAL radiation.
In comparison to solar radiation (heat emitted from sun) terrestial is a longer wave length
as earth’s heat is 1/20th that of the heat of sun surface. Gases in the air absorb the
terrestial radiation which stabilises air temperature. Greenhouse affect refers to the fact
that there are more gases (CO2) in the air so more heat is retained.
o Gases that contribute to terrestial radiation absorption are: water vapour, CO2,
methane CH4, ozone O3 and nitrous oxide N2O.
 If global warming is occurring then as the earth warms up we are more likely to get tropical
diseases, aided by an increase in insect vector numbers. Eg,Dengue fever, Ross River fever
Bushfires and radiant heat:
Smoke irritation signs: itchy eyes, sore throat, runny nose and general coughing. Healthy adults
with short exposures should recover quickly but children, elderly, smokers and people with preexisting lung conditions are more sensitive and should avoid smoke exposure.
Overall effects of bushfires include increased mortality from exacerbations of resp/cardiac
conditions, psychological problems (post traumatic stress disorder, major depression) and
decreased water quality (GI complaints).
EPA has bushfire alert levels that reflect changes in AIR QUALITY, related to the visibility, from
>20km (healthy) to <5 but >1km (very unhealthy) – postpone sporting events, stay indoors etc.
Non-ionising radiation:
Ultraviolet Radiation: from the sun; has three bands:
i.
UVA = longest wave with lowest frequency. Goes DEEP INTO SKIN causing long term
damage like wrinkles, sagging, blotchiness, and contributes to skin cancer.
ii. UVB = middle length  what we are EXPOSED TO IN SUNLIGHT. Ie. causes sunburn and
skin cancer. Reaches TOP LAYER of skin and is the main cause of tanning/sunburn. Also
contributes to skin cancer.
iii. UVC = shortest wave, highest frequency = IONISING RADIATION. All is absorbed in the
upper atmosphere but it splits )2 into ozone. Ozone reacts and some (but NOT ALL) of the
UVB is absorbed.
Sunsmart UV alert is issued when the UV Index is higher then 3 – largely determined by latitude,
time of year and time of day.
UPF =ultraviolet protection factor for clothing.
Sunscreen: can absorb and reflect UV radiation to prevent it from reaching the skin. Broad
spectrum protects against UVA and UVB.
SPF = Sun Protection Factor and tells you level of sun protection. SPF 30 protects skin from 97% of
radiation. No sunscreen protects from 100% UV radiation.
Wear hats, clothes etc and stay in shade (protects from 75% of UV radiation).
UV Radiation and Eye damage:
 Short term eye damage = excessive blinking, sunburn of cornea, difficulty looking at light
 Long term eye damage = cataracts (cloudy lens), solar keraropathy (cloudiness over
cornea), conjunctiva cancer, skin cancer of eyelids
 WEAR SUNGLASSES that meet the Australian Standard
Session 5: Knowledge and Advocacy
Sustainability = looks ahead to future generations
Diversity = looks around us now.
Populations are generally more concerned with environmental health effects that take time to
develop ie. cancer, birth defects. Need to use epidemiological studies and EBCP to ascertain
whether there is a causal relationship:
 Need to look for potential BIAS
 Need to do statistical test to see if CHNACE could explain findings
 Need to allow for CONFOUNDERS
Difficulties with epidemiological studies are that there are different levels of exposure, expense,
oftem multiple comparisons are made with same data set
Community based advocacy groups
1. Greenpeace – action to expose environmental problems and force solutions for a green
and peaceful future. Against violence.
2. Friends of the Earth (FoE) – works for a world where environmental protection, social
justice and econominc welfare for all people go hand in hand.
3. Worldwide fund for Nature (WWF) – stop degradation of the planet’s natural environment
and build a future in which humans live in harmony with nature.
4. Doctors for the Environment Australia – utilise medical profession to address the ill health
resulting from damage to the natural environment at local, national and global levels.
Voluntary organisation of doctors, based in Switzerland.
Risk Communication
Doctors main role involved in terms of “risk communication” is to advise individual patients in
regards to whether an exposure is causing the patent’s health problem.