MPH 540 Week 2 Environmental Hazard Analysis Example

Particles Too Small to See: Fine Particulate Air Pollution From a Steel Mill, a Highway and Wildfire Smoke in One Southern Colorado County

[Student Name]

University of Phoenix

MPH/540: Environmental and Occupational Health Management

Week 2 Assignment

[Instructor Name]

[Date]

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

At a spring meeting at an elementary school on the east side of the composite southern Colorado county, a mother described how her nine-year-old son used his rescue inhaler more on hazy summer days and on mornings when the air near the steel mill smelled of metal. She asked the environmental health staff a simple question: what is in the air, and is it hurting my son? This paper answers her question by analyzing fine particulate matter in the county.

The Agent

Fine particulate matter, called PM2.5, is a mixture of airborne particles 2.5 micrometers or smaller, roughly one-thirtieth the width of a human hair. The particles are a blend of soot, metals, sulfates, nitrates and organic compounds. Their small size lets them bypass the defenses of the nose and throat, lodge deep in the lungs and, for the smallest, pass into the bloodstream, where they promote inflammation affecting the heart and blood vessels.

Source One: The Steel Mill

The steel mill on the county's south side is the largest industrial source. Melting scrap in electric arc furnaces releases metal-bearing particles, and material handling adds dust. The mill operates under a state air permit and reports emissions annually. Emissions have fallen over the past two decades as controls improved, but residents in the neighborhoods closest to the mill still report dust on cars and windowsills.

Source Two: The Highway Corridor

An interstate highway cuts through the county's older neighborhoods. Diesel trucks and heavy traffic release combustion particles and stir road dust. Concentrations near major roads are highest within a few hundred meters and fall off with distance, so homes and schools along the corridor carry a larger share of the traffic burden than those a mile away.

Source Three: Wildfire Smoke

Wildfire smoke is the fastest-growing source. On several summer days in recent years, smoke from fires in the mountains and in other states pushed daily PM2.5 levels to many times their usual values. Unlike the mill and the highway, smoke affects the whole county at once and cannot be controlled locally, though its effects can be reduced.

What the Monitors Show

The county has one regulatory monitor operated by the state, located downtown. Annual average PM2.5 there has run below the national annual standard in most recent years, but daily readings spike during smoke events. A pilot network of eight low-cost sensors placed last year found that readings on the east side near the mill and the highway ran higher than downtown on most days, suggesting that one monitor understates exposure in the neighborhoods that face the most sources.

Exposure Pathways

Inhalation is the pathway. Exposure depends on outdoor concentration, time spent outdoors, how much outdoor air enters homes and breathing rate. Children breathe more air per pound of body weight than adults and spend more time outdoors, which increases their dose. Outdoor workers breathe hard for hours in whatever air the day brings.

Long-Term Health Effects

Long-term exposure shortens lives. In a cohort of 60.9 million Medicare beneficiaries followed from 2000 through 2012, deaths from all causes climbed 7.3% for every added 10 micrograms per cubic meter of annual PM2.5; limited to years with PM2.5 below 12 micrograms, the same increase carried a 13.6% rise in the risk of death, with steeper risk among male, Black and Medicaid-eligible enrollees (Di et al., 2017). There was no safe floor: harm appeared even in air that met the national standard of the time.

The Payoff of Cleaner Air

Reductions bring gains. Across 51 metropolitan areas, a decline of 10 micrograms per cubic meter in fine particles from the early 1980s to the late 1990s was associated with an increase in life expectancy of about 0.61 years, and cleaner air accounted for as much as 15% of the overall life expectancy gain in those areas (Pope et al., 2009).

Short-Term Effects of Smoke

Short bursts of smoke also harm health. A critical review of the smoke literature judged the link to breathing problems the most consistent finding, with flare-ups of asthma and of COPD standing out; the reviewers saw mounting support for links to respiratory infections and to deaths from all causes, but heart outcomes gave mixed results (Reid et al., 2016). The mother's observation about her son on hazy days is consistent with this evidence.

Who Breathes More

Exposure is not shared evenly. A national analysis linked fine particle pollution to the consumption that causes it and found that non-Hispanic white Americans breathe about 17% less PM2.5 than their consumption produces, while Black and Hispanic Americans bear 56% and 63% more, respectively; exposure fell by about half from 2002 to 2015 for all groups, but the inequity persisted (Tessum et al., 2019).

The Local Pattern

The county's east side mirrors the national pattern. Its neighborhoods are largely Hispanic and lower income, sit closest to the mill and the highway and have older homes that let in more outdoor air. Their residents contribute little to the traffic that passes through but breathe much of it.

Indoor Air

Because residents pass most hours inside, the air in homes counts as much as the air outdoors. Older homes with gaps around doors and windows let smoke in easily. Gas stoves, smoking and wood heating add particles. Households without air conditioning open windows on hot days, including smoky ones, which ties the heat and smoke problems together.

Susceptible Groups

Children with asthma, older adults, pregnant residents and people with heart or lung disease are most susceptible. Outdoor workers at construction sites and farms face long exposures during smoke events. People experiencing homelessness have almost no way to reduce exposure.

Recommendations for the Mill

The department will ask the state to add a fence-line monitor near the mill and will meet with the company about dust controls for material handling, sharing sensor data to focus the discussion.

Recommendations for the Highway

The department will work with the school district to review air filtration in the two schools nearest the highway, and with planners to discourage new schools, child care centers and senior housing within a few hundred meters of the corridor.

Recommendations for Smoke

For smoke, the goal is to reduce exposure rather than emissions. The department will issue alerts in English and Spanish when sensors show unhealthy levels, provide portable air cleaners to households with children who have asthma, set up clean-air rooms in libraries and senior centers and advise employers on reducing outdoor work during smoke events.

Monitoring and Data

Expanding the sensor network to 20 locations and publishing a public map will let residents see conditions where they live. Linking daily readings with emergency visits for asthma will show whether interventions reduce harm.

Answering the Mother

The department's answer to the mother was honest: the air on the east side carries more fine particles than downtown, research shows those particles harm children's lungs and shorten lives and her son's pattern fits the evidence. Staff enrolled her household in the air cleaner program and added her son's school to the filtration review.

Limits

Low-cost sensors are less precise than regulatory monitors and can overstate readings in humid conditions, so their data will be adjusted against the state monitor. The analysis cannot separate the mill's contribution from the highway's without source-specific sampling.

Conclusion

Fine particulate matter is the county's most widespread environmental hazard, drawn from a steel mill, a highway and wildfire smoke. National cohorts show harm even below current standards and gains in life expectancy when levels fall. Evidence on wildfire smoke explains children's asthma on hazy days, and research on pollution inequity explains why the east side breathes more. Recommendations target each source and the residents who bear the most exposure.

References

Di, Q., Wang, Y., Zanobetti, A., Wang, Y., Koutrakis, P., Choirat, C., Dominici, F., & Schwartz, J. D. (2017). Air pollution and mortality in the Medicare population. New England Journal of Medicine, 376(26), 2513-2522. https://doi.org/10.1056/NEJMoa1702747

Pope, C. A., Ezzati, M., & Dockery, D. W. (2009). Fine-particulate air pollution and life expectancy in the United States. New England Journal of Medicine, 360(4), 376-386. https://doi.org/10.1056/NEJMsa0805646

Reid, C. E., Brauer, M., Johnston, F. H., Jerrett, M., Balmes, J. R., & Elliott, C. T. (2016). Critical review of health impacts of wildfire smoke exposure. Environmental Health Perspectives, 124(9), 1334-1343. https://doi.org/10.1289/ehp.1409277

Tessum, C. W., Apte, J. S., Goodkind, A. L., Muller, N. Z., Mullins, K. A., Paolella, D. A., Polasky, S., Springer, N. P., Thakrar, S. K., Marshall, J. D., & Hill, J. D. (2019). Inequity in consumption of goods and services adds to racial-ethnic disparities in air pollution exposure. Proceedings of the National Academy of Sciences, 116(13), 6001-6006. https://doi.org/10.1073/pnas.1818859116