Samenvatting Environmental Health
MODULE 1: ENVIRONMENTAL HEALTH AND THE
BURDEN OF DISEASE
A. Context
What is health?
- WHO (1948): “Health is a state of
complete physical, mental and
social well-being and not merely
the absence of disease or
infirmity.”
- Aspects:
o Individual lifestyle
networks
o Social and community
networks (influences
your individual lifestyle)
o Living and working conditions influence yellow and orange ones
o Increasing levels? Harder to influence as an individual
- Approaches to health
o Individual level:
health care professionals (doctors, nurses, psychologists, physiotherapists, …)
o Population level: public health
What is public health?
- WHO: “The art and science of preventing disease,
prolonging life and promoting health through the
organized efforts of society.”
Approaches to public health
- Surveillance: The process of collecting, managing, analyzing,
interpreting, and reporting information on the status of
diseases, conditions, or populations
o → Establish health objectives and priorities
o Example: monitoring evolution of covid patients and hospital admittances
1
, - Health services
o To organize screening for example
- Disease prevention
o Primary prevention – before the disease
• E.g. covid: washing hands
o Secondary prevention – early diagnosis
• E.g. breast cancer screenings
o Tertiary prevention – slow progression
• E.g. exercises for people with dementia
- Health promotion
o E.g. promote active travel, taking the stairs, …
o This also means less emissions, also healthy
- Health protection
o Standards for air and water quality
o Figure below: levels op PM2,5 compared to EU and WHO regulations
What is environmental health?
- “covers all physical, chemical and (non-infectious) biological factors external to the
human body, which may affect health”
o Non-infectious: COVID is not part of environmental health
- Example: only the red circle is environmental health, not the uptake of fatty acids
- We are exposed to enormous amounts of factors
o Epidemiology: checking if what they see in the lab is visible in people /
populations too (counting groups of people and comparing them)
o E.g. Sometimes you see a bad effect of a pollutant in the lab, but not in the
population → possible that being active reduces the effect
2
, Disciplines
- Environmental toxicology: study of causal mechanisms between exposure and
subsequent development of disease in animal models or cells
- Environmental (and occupational) epidemiology: study of associations between
exposure to environmental/occupational agents and subsequent development of
disease in populations
- Health protection: sub-discipline of public health that has the objective of minimizing
the exposure to health hazards in order to protect the population by ensuring
environmental, occupational, toxicological and food safety
- Policy: legislation to protect the population
B. Historical case studies
Meuse Valley fog of December 1930
- More than 10 times the normal mortality rate
- International media attention
- Cause?
o Fumes, gases and dusts released by the local industry ( ~30 substances)
o SO2 was the only one released at enough [] to cause symptoms and death
- Why the meuse valley?
o Meteorology
• Anticyclonic conditions (high atmospheric pressures)
• Very feeble (1–3 km/h) easterly wind (from Liège into the valley).
• Temperature inversion above the chimneys in the valley
London fog in December 1952
- Painting Claude Monet – The houses of Parliament, sunset
- Graph: SO2 levels vs mortality/week
o Clearly a peak in both
o Afterwards both drop, but mortality stays higher
• = delayed effect (typical for environmental health)
- 4000 excessive deaths during the
week of fog
- 8000 excessive deaths in total
3
, Asthma outbreaks in Barcelona 1981-1986
- Investigation of 12 asthma outbreaks in the 80s
- Emergency rooms noticed a lot of people coming in with symptoms within a couple of
hours → thought of air pollution → investigation: mapped the cases, found point source
- Source: soybean unload (yay, meat farming) → solution found
Many other examples
Takeaway messages
- Outbreaks: not only about infectious diseases
- Meteorology and air pollution (link with climate change)
- Short-term effects vs long-term effects (see next part – burden of disease)
4
MODULE 1: ENVIRONMENTAL HEALTH AND THE
BURDEN OF DISEASE
A. Context
What is health?
- WHO (1948): “Health is a state of
complete physical, mental and
social well-being and not merely
the absence of disease or
infirmity.”
- Aspects:
o Individual lifestyle
networks
o Social and community
networks (influences
your individual lifestyle)
o Living and working conditions influence yellow and orange ones
o Increasing levels? Harder to influence as an individual
- Approaches to health
o Individual level:
health care professionals (doctors, nurses, psychologists, physiotherapists, …)
o Population level: public health
What is public health?
- WHO: “The art and science of preventing disease,
prolonging life and promoting health through the
organized efforts of society.”
Approaches to public health
- Surveillance: The process of collecting, managing, analyzing,
interpreting, and reporting information on the status of
diseases, conditions, or populations
o → Establish health objectives and priorities
o Example: monitoring evolution of covid patients and hospital admittances
1
, - Health services
o To organize screening for example
- Disease prevention
o Primary prevention – before the disease
• E.g. covid: washing hands
o Secondary prevention – early diagnosis
• E.g. breast cancer screenings
o Tertiary prevention – slow progression
• E.g. exercises for people with dementia
- Health promotion
o E.g. promote active travel, taking the stairs, …
o This also means less emissions, also healthy
- Health protection
o Standards for air and water quality
o Figure below: levels op PM2,5 compared to EU and WHO regulations
What is environmental health?
- “covers all physical, chemical and (non-infectious) biological factors external to the
human body, which may affect health”
o Non-infectious: COVID is not part of environmental health
- Example: only the red circle is environmental health, not the uptake of fatty acids
- We are exposed to enormous amounts of factors
o Epidemiology: checking if what they see in the lab is visible in people /
populations too (counting groups of people and comparing them)
o E.g. Sometimes you see a bad effect of a pollutant in the lab, but not in the
population → possible that being active reduces the effect
2
, Disciplines
- Environmental toxicology: study of causal mechanisms between exposure and
subsequent development of disease in animal models or cells
- Environmental (and occupational) epidemiology: study of associations between
exposure to environmental/occupational agents and subsequent development of
disease in populations
- Health protection: sub-discipline of public health that has the objective of minimizing
the exposure to health hazards in order to protect the population by ensuring
environmental, occupational, toxicological and food safety
- Policy: legislation to protect the population
B. Historical case studies
Meuse Valley fog of December 1930
- More than 10 times the normal mortality rate
- International media attention
- Cause?
o Fumes, gases and dusts released by the local industry ( ~30 substances)
o SO2 was the only one released at enough [] to cause symptoms and death
- Why the meuse valley?
o Meteorology
• Anticyclonic conditions (high atmospheric pressures)
• Very feeble (1–3 km/h) easterly wind (from Liège into the valley).
• Temperature inversion above the chimneys in the valley
London fog in December 1952
- Painting Claude Monet – The houses of Parliament, sunset
- Graph: SO2 levels vs mortality/week
o Clearly a peak in both
o Afterwards both drop, but mortality stays higher
• = delayed effect (typical for environmental health)
- 4000 excessive deaths during the
week of fog
- 8000 excessive deaths in total
3
, Asthma outbreaks in Barcelona 1981-1986
- Investigation of 12 asthma outbreaks in the 80s
- Emergency rooms noticed a lot of people coming in with symptoms within a couple of
hours → thought of air pollution → investigation: mapped the cases, found point source
- Source: soybean unload (yay, meat farming) → solution found
Many other examples
Takeaway messages
- Outbreaks: not only about infectious diseases
- Meteorology and air pollution (link with climate change)
- Short-term effects vs long-term effects (see next part – burden of disease)
4
