ENVIRONMENT & HEALTH Dept. of Public Health Faculty of Medicine - Padjadjaran University Bandung.

ENVIRONMENT & HEALTH

Dept. of Public HealthFaculty of Medicine - Padjadjaran

UniversityBandung

Learning Objective:• To explain the basic relationship b/w

environmental factors & health, & how the interrelationship b/w economic development, the environment & health can be seen in an ecosystem framework

• To interpret environmental health in historical context w/ respect to changes in technology, economic development & social organization

• To describe the basic requirements for a healthy environment

• To explain the basic issues & concerns w/ respect to methods of measuring environmental quality, exposure & health effects

• To describe the larger socio-economic issues affecting environmental health

ReferencesReferences

• Yassi A, Kjellström T, de Kok T, Guidotti Yassi A, Kjellström T, de Kok T, Guidotti TL. TL. Basic environmental health. Basic environmental health. Chapter 1: Introduction. New York: Chapter 1: Introduction. New York: Oxford University Press, 2001Oxford University Press, 2001

• Smith KR, Corvalán CF, Kjellström T. Smith KR, Corvalán CF, Kjellström T. How much global ill health is How much global ill health is attributable to environmental factors? attributable to environmental factors? Epidemiology, Epidemiology, September 1999, Vol. September 1999, Vol. 10(5):573-8410(5):573-84

BIRTH, LIFE, DEATH & THE ENVIRONMENT

First human beings faced hostile environment shorter life expectancy To survive, the first humans had to cope w/: the constant search for sufficient food & drinking water while avoiding

plants contained natural toxins or rancid infected meat infections & parasites spread from person to person or animal to

person, via food, drinking water, or insect vectors injuries from falls, fires, & animal attacks cold & hot temperatures, rain, snow, natural disasters & other adverse

events

Traditional hazards Modern hazards

What is What is ‘environment’‘environment’??

(all) that which is external to the individual human host. (It) can be divided into physical, biological, social, cultural, any or all of which can influence health status in populations (Last, 1995)

• Environmental causes of diseases Environmental causes of diseases would be all those that are not would be all those that are not geneticgenetic

• ‘‘Nature’ vs ‘nurture’Nature’ vs ‘nurture’

• Environmental factors include all Environmental factors include all those that affect the organism those that affect the organism after conception regardless of after conception regardless of whether they are mediated by whether they are mediated by social conditions & individual social conditions & individual choice or through environmental choice or through environmental mediamedia

Simplified illustration of integration within the comparatively simple pine forest ecosystem

Ecosystem any spatial or organizational unit which

includes living organisms & nonliving substances interacting to produce exchange of materials b/w the living & nonliving parts

Basic components: abiotic substances producer organisms consumer organisms decomposer organisms

Basic components of an ecosystem

Basic plantnutrients

PRODUCERS• Green plants• Bacteria

PRIMARY CONSUMERS• Herbivores• Plant parasites

SECONDARY CONSUMERS• Omnivores• Carnivores• Animal parasites• Scavengers

DECOMPOSERS• Saprophytic bacteria• Fungi

HEALTH

The scale & nature of human activities

(agricultural, industrial, & energy production, the use & management of water & wastes; urbanization; the

distribution of income & assets within & between countries; the quality of health services; & the extent of protection of

the living, working, & natural environment

Physical & chemical environment

(air, water, food & soil chemical composition including radiation; climate including temperature,

humidity, precipitation, & seasonal changes)

Biological environment(type & distribution of pathogens & vectors, as

well as their habitats)

Source: Yassi et al., 2001 (adapted from WHO 1992)

Sustainable Development

development that meets the needs of the present development that meets the needs of the present without compromising the ability of future without compromising the ability of future generations to meet their own needsgenerations to meet their own needs

(WCED, 1987)(WCED, 1987)

Human beings are at the center of concerns for Human beings are at the center of concerns for sustainable development. They are entitled to a sustainable development. They are entitled to a healthy & productive life in harmony with naturehealthy & productive life in harmony with nature

(UN, 1993)(UN, 1993)

Environmental HealthEnvironmental Health

comprises those aspects of human health, comprises those aspects of human health, including quality of life, that are including quality of life, that are determined by physical, biological, social determined by physical, biological, social and psychosocial factors in the and psychosocial factors in the environmentenvironment

refers to the theory & practice of refers to the theory & practice of assessing, correcting, controlling, & assessing, correcting, controlling, & preventing those factors in the preventing those factors in the environment that can potentially affect environment that can potentially affect adversely the health of present & future adversely the health of present & future generationsgenerations

(WHO, 1993)(WHO, 1993)

Environmental Health Science

• hazards in the environment, their effects on health & the variations in sensitivity to exposures within populations

• development of effective means to protect against hazards in the environment

EEtthhiiccss????

Ethical dilemma

Any control limiting the exploitation of resources may inhibit an individual’s or a community’s attempts to

enhance their standard of living infringing on their rights & freedoms as well as

decreasing their ability to maintain health

VS

Any action to protect the environment & maintain the integrity of the ecosystem is justified regardless of the

impact on human activity & health

UN:1st Order Principle:

Ensuring human survival should be taken as a first-order principle

Universal Declaration of Human Rights (UN, 1948)

‘all people have the right to a standard of living adequate for the health and well-being of themselves & their family, including food, clothing, housing, health care, and the necessary social services’

2nd Order Principle:

Respect for nature & control of environmental degradation

Humans have extraordinary abilities to adapt to and influence their environment to meet their needs Many ways to make the environment healthierEnvironmental health hazards are beyond

the control of the affected individual, e.g.:

• industrial pollution• poor services of drinking water &

sanitation• poor housing & town planning• lax control over eating establishments or

food industry• poor quality roads• poor conditions in the workplace

Historical Perspective• 1st environmental crisis

• 2nd wave of environmental concern

• 3rd wave of environmental concern

Basic Requirements for a Healthy Environment

• Clean air

• Safe & sufficient water

• Adequate & safe food

• Safe & peaceful settlement

• Stable global environment

Measurement Methods

EnvironmentalQuality

Monitoring

HumanExposure

Monitoring

HealthImpact

Assessment

Some pathways for translation of

epidemiological evidence into policyRegulatory

OHS

Environmental Quality

Drug Safety

Public Health Recommendations

Vaccination

Diet

Smoking

Legal System

Cause of injury

Health-care delivery

Practice guidelines

Outcome assessment

Risk management policies are intended to assure that exposures convey an acceptable level of risk, whether in the WP or the general environment

Quantitative Risk Assessment (NRC, 1983):

• Hazard identification – is there a hazard?• Dose-response – what is the relationship

b/w exposure or dose & risk?• Exposure assessment – what is the

distribution of exposure?• Risk characterization – what is the risk to

the population?

THE PATHWAYS FROM SOURCES & MEDIA OF EXPOSURE TO HEALTH EFFECTS (NRC, 1991)

Air FoodSoilWater

Media of exposure ‘source’

Transport & fate

Routes of entry

InhalationIngestion

Skin

Exposure

Internal dose

Biologically effective dose

Health & comfort effects

Applic

ati

ons

Environmental epidemiology

Risk assessment

Risk management

Intervention, prevention & diagnosis

Physicoharmacokineticmodels

Pharmacodynamicsmodels

Exposure metrics in environmental epidemiology

• Cumulative exposure• Exposure during a susceptibility window• Recent exposure• Time since first exposure• Age at first exposure• Exposure rate• Peak exposure• Exposure above threshold

Concept of DALYa measure for the burden of disease that takes into account premature death & loss of healthy life resulting from disability disabilities: physical or mental

Intended use is to assist:• in setting health service priorities• in identifying disadvantaged groups & targeting of health

interventions• in providing a comparable measure of output for

intervention, program & sector evaluation & planning

One DALY is thus one lost year of healthy life

ESTIMATED GBD FROM SELECTED ENVIRONMENTAL THREATS, 1990 & POTENTIAL WORLDWIDE REDUCTIONS THROUGH INTERVENTION IN THE

WORKPLACE & AMBIENT ENVIRONMENT

Type of environment & principal related diseasesa

Burden from these diseases (millions of DALYs/year)

Reduction achievable

through feasible interventions (%)b

Burden averted by feasible

interventions (millions of

DALYs/year)

Burden averted per 1000

population (DALYs/year)

OCCUPATIONAL 318 - 36 7.1

Cancers 79 5 4 0.8

Neuropsychiatric 93 5 5 0.9

Chronic respiratory 47 5 2 0.5

Musculoskeletal 18 50 9 1.8

Unintentional injury 81c 20 16 3.1

URBAN OUTDOOR AIR

Acute respiratory infections 123 5 6 1.2

Chronic respiratory diseases 47 5 2 0.5

ROAD TRANSPORT

(motor vehicle injuries) 32 20 6 1.2

All the above 473d - 50 10.0

Source: World Bank, 1993

ESTIMATED BURDEN OF DISEASE FROM HOUSEHOLD ENVIRONMENTS IN DEVELOPING COUNTRIES, 1990 & POTENTIAL REDUCTION THROUGH INTERVENTIONS

Principal diseases related to poor

household environmentsa

Relevant environmental

problem

Burden from these diseases in

developing countries (millions

of DALYs/year)

Reduction achievable

through feasible interventions (%)b

Burden averted by feasible

interventions (millions of

DALYs/year)

Burden averted per 1000

population (DALYs/year)

Tuberculosis Crowding 46 10 5 1.2

Diarrheac Sanitation, watersupply, hygiene

99 40 40 9.7

Trachoma Water supply, hygiene

3 30 2 0.3

Tropical clusterd Sanitation, garbage disposal, vector breeding

8 30 2 0.5

Intestinal worms Sanitation, water supply, hygiene

18 40 7 1.7

Respiratory infections

Indoor air pollution, crowding

119 15 18 4.4

Chronic respiratory diseases

Indoor air pollution 41 15 6 1.5

Respiratory tract cancers

Indoor air pollution 4 10 <1 0.1

All of the above 338 - 79 19.4 Sourc

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PROPORTION OF GLOBAL DALYS ASSOCIATED WITH ENVIRONMENTAL EXPOSURES, 1990

% of all DALYs

Global DALYs (thousands)

Environmental fraction (%)

Environmental DALYs (thousands)

All age groups

Age 0-14 years

Acute respiratory infections 116,696 60 70,017 5.0 4.50

Diarrheal diseases 99,633 90 89,670 6.5 6.10

Vaccine-preventable infections 71,173 10 7117 0.5 0.49

Tuberculosis 38,426 10 3843 0.3 0.04

Malaria 31,706 90 28,535 2.1 1.80

Unintentional injuries 152,188 30 45,656 3.3 1.60

Intentional injuries 56,459 NE NE

Mental health 144,950 10 14,495 1.1 0.08

Cardiovascular diseases 133,236 10 13,324 1.0 0.12

Cancer 70,513 25 17,628 1.3 0.11

Chronic respiratory diseases 60,370 50 30,185 2.2 0.57

Total these diseases 975,350 33 320,470 23.0 15.40

Other diseases 403,888 NE NE

Total all diseases 1,379,238 (23) (320,470)

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Links b/w environmental & occupational health

• Importance of the workforceHealthy, well-trained & motivated workforce productivity & wealth

• Linked E & O hazardsThe source of the E & O hazards is often the same

• Common approaches & human resourcesThe scientific knowledge & training required to assess & control EH hazards are generally the same skills & knowledge required to address health hazards within the WP (e.g. toxicology, epidemiology, occupational hygiene, ergonomics & safety engineering

• The workplace as a sentinel for environmental hazardsEH hazards have often been first identified from observations of adverse health effects in workers. Information on OH effects of many toxic exposures has been used to calculate the health risk to the wider community

• Total exposure conceptNot enough to assess the exposure to a hazard from just one source

• Consistency in setting standardsEH standards are usually much stricter than OH standards

• Incentives for preventionAlthough the WP is usually the site of more intense exposures, the impact of these hazards on the general public has often been a major force in stimulating cleanup efforts, both inside the WP & in the surrounding community

Comparison between WHO Health-Based Guidelines for Air in the Workplace &

in the General Environment

ChemicalWP Guideline g/m3

(8-hr mean)

General Environment Guideline g/m3

(annual mean)

Lead 30 – 60 0.5 – 1.0

Cadmium 10 0.01 – 0.02

Manganese 300 1

Mercury 50 1

Formaldehyde 500 100 (24 hours)

Nitrogen dioxide 900 150 (24 hours)

Sulfur dioxide 1300 50

Source: WHO, 1987 & several Technical Reports

OBSTACLES & OPPORTUNITIES• Demographic issues

Size of the population level of consumption• Poverty

The poor usually lack a minimum standard of living (e.g. adequate food, safe & sufficient supplies of water, secure shelter, access to education & health care, & provision for the removal of domestic wastes

• Consumption patternsMajor difference in consumption patterns b/w different countries & b/w different groups within countriesRees & Wackernagel (1992) characterized the land area necessary to sustain current levels of resource consumption & waste discharge by a population as its ecological footprint.The ecological footprints of high income cities are hundreds of times larger than their politic or geographical area & are much larger than the ecological footprints of lower income communities

• Macroeconomic policiesInfluence the use & degradation of natural resources, b/c can affect consumer demand & the prices of natural resourcesThe effects are felt most directly at the level of an individual’s purchasing power

EH Professionals

• EH Officer

• EH Technician

• Environmental Inspector

• Epidemiologist

• Ergonomist

• Health Physicist

• Health Policy Analyst

• Laboratory Analytical Scientist

• Occupational Hygienist• OH Nurse• OEH Physician• OHS Inspector• Sanitary Engineer• Safety Professional• Statisticians• Toxicologist

Thank you ….