PM10 dust from a dry lakebed, logged on a school-roof monitor and converted into AQI values, is set against the 24-hour federal standard in this SC415 Unit 4 analysis. Searches like "sc 415 unit 4 assignment example", "sc415 unit 4 sample" and "sc415 unit 4 example" land here.
What a finished SC415 Unit 4 air quality analysis looks like
Around six pages with a chart and two tables. The chart plots 365 daily PM10 averages as bars with a horizontal line at 150 micrograms per cubic meter, the 24-hour national standard, so the spring cluster of exceedances is visible before any sentence describes it. Table 1 lists the eleven days above the line with date, concentration, AQI value and category. Table 2 works the conversion for two of those days: 212 micrograms becomes an AQI of 129, unhealthy for sensitive groups, and 380 becomes 237, very unhealthy, each with its breakpoints and the linear interpolation shown. Data provenance and the handling of missing days get one methods paragraph. The last section addresses the hourly peaks that daily averages flatten.
How a SC415 Unit 4 example is structured
Before any dust appears, the monitor is described, because every later claim depends on where it sits and what it records: one filter-based sampler, one 24-hour average per day, nine miles from the source. The standard comes next, stated in its legal form, not to be exceeded more than once per year on average over three years, and the paper notes that PM10 has carried no annual standard since 2006, which stops the analysis from averaging the year into a reassuring number. Conversion to AQI follows, framed as a communication tool derived from the standard rather than a second standard. Health meaning is kept to what the categories are designed to say. A closing section argues that a continuous monitor near the lakebed would capture wind-event peaks the school-roof data cannot.
One sampler on a school roof
Location, height, sampling method and data completeness are stated first. The monitor records a single average per day, which shapes every conclusion about wind events that last two or three hours.
The standard in its legal wording
The 150 microgram level is quoted with its form, an expected exceedance count, so eleven exceedance days are read against the allowance correctly instead of being counted as eleven violations.
Two conversions worked in full
Breakpoints, the interpolation formula and the arithmetic appear for 212 and 380 micrograms, and each result is rounded to a whole AQI number the way agencies report it.
Category wording and the classrooms below
Unhealthy for sensitive groups names children, older adults and people with heart or lung disease. The section ties that wording to the classrooms directly below the monitor.
Peaks a daily average hides
Wind records show gusts lasting two to three hours on exceedance days. The paper argues that hourly concentrations far above the daily figure are likely and that a continuous monitor would show them.
Where marks go in SC415 Unit 4
Graders of an air quality analysis generally look first for the right standard applied in its correct form, and papers that compare a daily value with an annual benchmark, or count every exceedance as a violation, lose accuracy credit at the root. Calculation credit follows from the AQI conversions: correct breakpoints, the interpolation shown and sensible rounding. Data handling is often a criterion of its own, so a stated source, a completeness figure and a note on missing days protect points that many drafts give away. Interpretation earns the rest when it links the category language to actual people near the monitor. Deductions appear for PM10 and PM2.5 treated as one pollutant, for microgram and milligram slips, and for health claims stronger than the index was designed to support.
Get a SC415 Unit 4 example written to your instructions
Download the monitor data for the site the SC415 Unit 4 prompt names, or note that the prompt supplies its own, then add the directions and rubric. Within 24-48h a first custom analysis, free of charge, charts the year, converts the worst days to AQI, arithmetic shown, and reads each against the correct standard.
SC415 Unit 4 questions, answered
Where can I get daily air monitoring data?
The EPA's outdoor air quality data site lets you download daily values by pollutant, county and monitor, and AirNow shows current and recent AQI readings. State air agencies often post the same data with more local notes. Record the monitor ID and the years you pulled, because a grader may check that your figures match the public record.
Is the AQI the same thing as the air quality standard?
No. The national standards are legal limits written as a concentration, an averaging time and a form. The AQI is a reporting scale built from those standards so the public can read one number, and an AQI of 100 sits near the standard for each pollutant. Use the standard for judgment and the AQI for communication.
Can low-cost sensors be used in this assignment?
Often yes, as supporting evidence. Consumer sensors report particle levels at far more locations, but their readings need correction and they are not the regulatory record. Many analyses pair one official monitor with nearby sensor data to show local variation, and they say clearly which numbers carry legal weight and which only suggest a pattern.