MPH 540 Week 1 The Ecological Basis of Health and Disease Example

River, Soil, Air and Heat: The Ecological Basis of Health in a Southern Colorado Steel County and What It Means for Public Health Management

[Student Name]

University of Phoenix

MPH/540: Environmental and Occupational Health Management

Week 1 Assignment

[Instructor Name]

[Date]

The county, its neighborhoods, programs and local observations are composites written for a model paper; research findings come from the sources cited.

In her first week, the new environmental health director of a composite southern Colorado county drove through its neighborhoods with a longtime inspector. In one afternoon she saw the river that runs through the city, the fenced remains of a smelter that closed a century ago, the steel mill that still employs hundreds and blocks of older homes baking in afternoon heat. The inspector said the county's health story was written in its environment. This paper applies the ecological basis of health to that story.

An Ecological View of Health

An ecological view treats human health as the product of interactions among people and their physical, chemical, biological and social environments. Health problems rarely have a single cause; they arise from systems that interact, such as housing, industry, water, climate and income. The approach borrows from ecology the idea that organisms and their surroundings shape each other over time. People change their environment by building mills, roads and homes; those changes then return to affect health, sometimes generations later, as the county's soils show. An ecological view also asks public health staff to look upstream, beyond individual behavior, to the conditions that make healthy choices easy or hard.

Planetary Health

A commission on planetary health argued that humanity's remarkable health gains of recent generations were achieved while degrading the natural systems on which health depends, and that continued degradation of climate, water, soils and biodiversity threatens to reverse those gains (Whitmee et al., 2015). The county's own history, with health and prosperity built on industry that left contaminated soils, illustrates the point on a local scale.

Exposure Pathways

Environmental health analysis follows exposure pathways: a source releases a contaminant, it moves through air, water, soil or food, people contact it and it enters the body. Breaking any link prevents harm. A contaminant sitting in deep soil under a parking lot poses little risk; the same contaminant in bare yard soil where toddlers play is a direct threat. Pathway thinking therefore directs attention to the points where people actually meet a hazard, and it identifies the practical places to intervene, such as covering soil, replacing a pipe or filtering indoor air. It also clarifies dose, because the amount that reaches the body depends on how long and how often contact occurs.

System One: Soil and Lead

The former smelter left lead and arsenic in soils across several neighborhoods, where many homes also predate the ban on lead paint. Children are exposed through soil and dust on hands and toys. Low levels matter: a pooled analysis of seven international cohorts found an IQ decrement of 6.2 points as blood lead rose from 2.4 to 30 micrograms per deciliter, with the steepest losses at the lowest levels, including 3.9 points between 2.4 and 10 micrograms per deciliter (Lanphear et al., 2005). There is no level of lead in a child's blood that can be called harmless.

System Two: Water

The river supplies drinking water after treatment and receives runoff from farms and streets. Water systems can fail, as Flint showed: after its drinking water source changed, the incidence of elevated blood lead levels in children rose from 2.4% to 4.9%, with the largest increases in disadvantaged neighborhoods (Hanna-Attisha et al., 2016). The county's water utility tests regularly, but aging service lines in older neighborhoods may contain lead.

System Three: Air

The steel mill, highway traffic, dust from dry fields and wildfire smoke from the mountains affect air quality. Fine particles aggravate asthma and heart disease. Neighborhoods near the mill and highway bear the most exposure. Air differs from soil and water in one important respect: residents cannot choose to avoid breathing it. A family can buy bottled water or cover a yard, but on a smoky day everyone downwind is exposed. Indoor air matters too, since older homes with gas stoves, poor ventilation and mold add their own burden to what drifts in from outside.

System Four: Climate and Heat

Summers are growing hotter. Heat interacts with other systems: it raises ozone formation, stresses older adults and outdoor workers and strains power grids. The county's July heat wave showed how quickly heat translates into illness, with emergency visits rising within a day of the temperature spike. Heat is also changing the other systems: drier summers raise dust, lengthen the wildfire season and lower river flows, which can concentrate contaminants in the water the utility must treat. Climate works less as a separate hazard than as a multiplier of the others.

How the Systems Interact

The four systems do not act alone. Older neighborhoods near the smelter site have lead in soil, older homes without air conditioning, fewer trees and more nearby traffic. The same residents face multiple exposures at once, and their effects can compound.

Social Factors

Social conditions determine who is exposed. The neighborhoods with contaminated soil and poor air are home to lower-income, largely Hispanic families, many of whom rent and cannot afford to move or renovate. Environmental justice asks why these burdens fall on them and how to share protection fairly.

Biological Factors

In the ecological view, social and biological factors meet in the body.

Biological factors shape susceptibility. Young children absorb more lead than adults and are more vulnerable to its effects. Older adults are more vulnerable to heat. People with asthma or heart disease suffer more from air pollution. Pregnancy adds another window of vulnerability, since lead stored in a mother's bones can cross the placenta. Susceptibility and exposure often cluster in the same households, which means a child in an older rental near the old smelter site may face both the highest exposure and the greatest sensitivity to it.

Implications for Management

An ecological view changes how a health department manages its work. Rather than separate programs for lead, air and heat, the department can target neighborhoods where exposures overlap, coordinate with housing, utilities, parks and industry and track combined burdens.

Priority One: Children and Lead

Expand blood lead testing for young children in affected neighborhoods, with soil testing and cleanup support for yards where children play. Because the steepest harm occurs at low levels, the department will follow up on children with any measurable increase rather than waiting for a high result, visiting homes to find the source.

Priority Two: Water Service Lines

Work with the utility to inventory and replace lead service lines, starting in neighborhoods with young children. Until lines are replaced, the department will distribute certified filters to households with infants and pregnant residents and explain in English and Spanish how to flush taps after water sits overnight.

Priority Three: Air

Add low-cost community air sensors near the mill and highway, calibrated against the state regulatory monitor, and share results publicly on a simple map. During wildfire smoke events, the department will issue alerts and lend portable air cleaners to families whose children have asthma.

Priority Four: Heat

Plant trees and expand cooling access in neighborhoods with the least shade, working with the parks department to prioritize blocks where surface temperatures run highest. The department will also build a list of older adults living alone who agree to receive check-in calls during heat alerts.

Priority Five: Data Integration

Build a neighborhood environmental health map combining soil, water, air, heat and health data to guide where to act first. The map will let staff see, block by block, where lead, poor air, heat and low income overlap, and it will show residents and commissioners why some neighborhoods receive more attention than others.

Limits

Many environmental exposures are poorly measured at the neighborhood level, and the effects of multiple exposures are hard to separate. The department will start with the best available data and improve it over time. Environmental improvements also take years to show health effects, so early evaluation will track exposures, such as soil lead and service lines replaced, before outcomes such as blood lead levels.

Conclusion

The inspector was right: the county's health is written in its environment. Viewed ecologically, lead in soil, water systems, air and heat interact and concentrate in neighborhoods with the least power to escape them. Evidence on low-level lead, a water crisis elsewhere and the costs of degrading natural systems supports a management approach that targets overlapping exposures and works across sectors.

References

Hanna-Attisha, M., LaChance, J., Sadler, R. C., & Champney Schnepp, A. (2016). Elevated blood lead levels in children associated with the Flint drinking water crisis: A spatial analysis of risk and public health response. American Journal of Public Health, 106(2), 283-290. https://doi.org/10.2105/AJPH.2015.303003

Lanphear, B. P., Hornung, R., Khoury, J., Yolton, K., Baghurst, P., Bellinger, D. C., Canfield, R. L., Dietrich, K. N., Bornschein, R., Greene, T., Rothenberg, S. J., Needleman, H. L., Schnaas, L., Wasserman, G., Graziano, J., & Roberts, R. (2005). Low-level environmental lead exposure and children's intellectual function: An international pooled analysis. Environmental Health Perspectives, 113(7), 894-899. https://doi.org/10.1289/ehp.7688

Whitmee, S., Haines, A., Beyrer, C., Boltz, F., Capon, A. G., de Souza Dias, B. F., Ezeh, A., Frumkin, H., Gong, P., Head, P., Horton, R., Mace, G. M., Marten, R., Myers, S. S., Nishtar, S., Osofsky, S. A., Pattanayak, S. K., Pongsiri, M. J., Romanelli, C., ... Yach, D. (2015). Safeguarding human health in the Anthropocene epoch: Report of The Rockefeller Foundation-Lancet Commission on planetary health. The Lancet, 386(10007), 1973-2028. https://doi.org/10.1016/S0140-6736(15)60901-1