Environmental Health – Part I:An Introduction

John Mulvaney, MHA, Ph.D. studentWalden University

PH 8165-4Instructor: Dr. Raymond Thron

Spring, 2009

Outline

Brief video Introduction to environmental health

– Definition(s)– Types of Hazards– Regulation

Discussion

Introduction

What is meant by environmental health (EH)?

Introduction

There are a number of “acceptable” definitions for the environment as it relates to health:

– Inner vs. Outer Environment: in this context, the environment is described in terms of within our bodies (inner) and external to our bodies (outer).

– Personal vs. Ambient Environment: differentiates based upon the environment we control (personal) and the environment in which we have very little or no control (ambient/work/outside).

– Gaseous, Liquid, and Solid Environments: describes the environment in terms of the state of matter (solid, liquid, gas) and how they interact with people (Moeller, 2005).

Introduction

Yet another, more encompassing definition is one that includes (Moeller, 2005):– Chemical Factors– Biological Factors– Physical Factors– Socioeconomic Factors

Introduction

Types of environmental hazards:– Radiation– Mercury– Lead– Pesticides– Industrial Chemicals– Violence?

Figure 1: Interaction with humans

Water:GI Tract

Skin

GI Tract:SkinSoil

Food:GI Tract

Air:LungsSkin

Human Being

Source: Moeller, 2005

Introduction

Environmental Hazards: Radiation

Ultraviolet light from the sun – skin cancer and melanoma

Radon gas – natural radioactivity – lung cancer? Early scandals with patent medicines and radium led

to regulation X rays used in medicine and dentistry Lessons on health effects of radiation learned from

atomic bombings in Japan

Environmental Hazards: Lead

Harmful to brain and nervous system, especially of children Contamination of drinking water by lead pipes and lead solder

for copper pipes Air pollutant from use in gasoline until banned in the 1980s Was used in paint until 1977 – still a threat in old housing –

peeling paint or contaminated dust Young children should be screened for blood lead levels

– Permissible levels have been steadily lowered

Source:

Schneider, M. (2006). Introduction to public health, second edition. Jones & Bartlett: Sudburry, MA.

Environmental Hazards: Pesticides

Pesticides and Industrial Chemicals Rachel Carson’s Silent Spring – 1962 – beginning of environmental

movement DDT and other pesticides– now banned PCBs – industrial uses

– Hudson River – contaminates fish– Yusho accident (Japan) – contamination of cooking oil – other similar

accidents– Production halted in US by 1977

Endocrine disrupters, affect reproduction, nervous system, immune system, maybe cancer

Soluble in fat, persist in environment, very stable

Source: Schneider, M. (2006). Introduction to public health, second edition. Jones &

Bartlett: Sudburry, MA.

Environmental Hazards

If interested in further information relating to these and other hazards please see the following:

Koller, K., et al, Recent Developments in Low-Level Exposure and Intellectual Impairment in Children. Environmental Health Perspectives, 112 (2004): 987-994

Clarkson, T. The Three Modern Faces of Mercury. Environmental Health Perspectives 110, Suppl. 1 (2002): 11-23

Alavanja, M., et al. Health Effects of Chronic Pesticide Exposure: Cancer and Neurotoxicity. Annual Review of Public Health 25 (2004): 155-197

Centers for Disease Control and Prevention. Third National Report on Human Exposure to Environmental Chemicals. Accessed at: http://www.cdc.gov/exposurereport/pdf/thirdreport.pdf on March 18, 2009.

Regulation

Regulation

Multitude of regulatory bodies involved with protection of the environment.

– Environmental Protection Agency http://www.epa.gov

– NIOSH (Occupational Safety)http://www.cdc.gov/niosh/

– Nuclear Regulatory Commissionhttp://www.nrc.gov

Laws/Regulations:– Clean Air Act– Clean Water Act– Executive Orders– Case law

EH cases that went to court and have had a judgment rendered. Can be used to set a precedent for other cases or rulemaking.

Environmental Health – Part II:Mitigating the law of unintended consequences. An application of systems thinking to environmental health.

John Mulvaney, MHA, Ph.D. studentWalden University

PH 8165 - 4Instructor: Dr. Raymond Thron

Spring, 2009

Outline

Law of unintended consequences Example:

– DDT and Malaria

A systems approach

Law of Unintended Consequences

Roughly equivalent to a really big “oops – didn’t see that one coming”

Similar concept in other disciplines:– Economics: externalities– Physics: Newton’s 2nd Law of Thermodynamics

For every action, there is an equal and opposite reaction

Example: DDT and Malaria

DDT had been used extensively to fight malaria since the 1940’s

Worked well for many years but…– 1972 book Silent Spring connected the use of

DDT with health effects on birds– Created a groundswell to eliminate the use of

DDT as a means of controlling the vector which spreads malaria (mosquito).

Example: DDT and Malaria

Dramatic increase in the number of reported cases and deaths from malaria from the 70’s forward (Roberts, 1997).

The alternative approach was to use non-DDT saturated bed nets (Economist, 2008).

Argument has been made that the ban was directly responsible?

Example: DDT and Malaria

The good news:– There is a strong push to make the eradication of

Malaria a reality– Realization that although DDT may have some

long-term effects, particularly in infants, the risks are not outweighed by benefits in the measured use of DDT in endemic countries (Mandavilli, 2006).

The Systems Approach

A systems approach makes reference to the concept of taking in the full picture with respect to an issue.

Draws from multiple disciplines in a concept that links the disciplines towards a common goal

Offers the public/environmental health community a “new frontier” in the ongoing effort to understand and prevent disease (Leischow, 2006).

The Systems Approach

More precisely:– Systems approaches draw from areas such as

control theory, social network theory, cellular automata, computational simulation…

– While the magnitude of approaches are vast, the concepts unify around a couple of core concepts

dynamics and complexity mechanical vs. biological (Trochim, 2006)

The Systems Approach

Trochim et al., 2006 – Used a concept mapping approach to

comprehend the vast literature regarding systems theory

– While there is a great deal of interest and momentum in systems theory in public health, there are some barriers/issues that need to be addressed

The Systems Approach

Concept mapping revealed 8 clusters of challenges– Support dynamic and diverse networks– Inspire integrative learning– Use systems measures and models– Foster systems planning and evaluation– Show potential of systems approaches– Explore systems paradigms and perspectives– Expand cross-category funding– Utilize systems incentives

The Systems Approach

How would a systems approach have changed the DDT scenario?

– Dynamics Account for the alternative of changes in genetic adaptation of

insects to build resistance to DDT Study and understand implications of banning a previously

effective strategy (prior to banning it)– Complexity

Understand the interactions of SES and disease as they relate to alternate strategies for Malaria eradication

If a more expensive alternative to DDT is developed, how will that impact the lesser developed countries in which the disease is endemic

The Systems Approach

Mechanics vs. Biology– Modeling the potential impact from a change in

use of DDT with bed nets– What are the biologic consequences to animal

populations, human populations, and the infectious agent from the different approach

The Systems Approach

Addressing the common misconceptions– Not a rejection of traditional scientific views

Actually enables a more broad and encompassing application of solid scientific evidence

– Does not lack scientific rigor Takes a more nuanced view of the situation Roots are based in mathematics, biology, physics

(Trochim, 2006)

The Systems Approach

Any questions?

References:

Leischow, S., & Milstein, B., (2006). Systems thinking and modeling for public health

practice. American Journal of Public Health,96(3), 403-405.

Mandavilli, A., (2006). DDT returns. Nature Medicine. 12(8), 870-871.

Roberts, D., Laughlin, L., Hsheih, P., &Legters, L., (1997). DDT, global strategies, and a malaria control crisis in South America. EmergingInfectious Diseases. 3(3), 295-302.

References:

The Economist, (2008). One quick shot may not be enough. April 10, 2008 edition. Accessed at: http://www.economist.com/world/internati

onal/displaystory.cfm?story_id=11019802

Trochim, W., Cabrera, D., Milstein, B., Gallagher, R., & Leischow, S., (2006).Practical challenges of systems thinking

and modeling in public health. American Journal of Public Health, 96(3), 538-546.