• Humboldt-Del Norte Unit
• Shasta-Trinity Unit

Recently, the American Lung Association (ALA) issued its State of the Air 2017 report in which “report cards” are given for major areas throughout the US. The report cards have been an annual event by the ALA for many years now. The report cards grade 726 counties in the US which operate ambient particulate and ozone monitors over a three year period. The grade is weighted and seeks to reflect the number of days the area exceeds AQI Moderate level for 24-hr PM2.5 averages and 8-hr Ozone levels.

Typically the only county in the North Coast Unified AQMD that is able to receive a grade (i.e. there is monitoring data available) is Humboldt County, which is usually a grade of “A” for both High Ozone Days and High Particle Pollution Days (see the 2016 ALA report). However, this year the 2017 ALA report gave Humboldt County a “C” grade for High Particle Pollution Days in error upon its review of EPA data.

ALA gets their data from the EPA’s Air Quality System and for this year’s report, they use 24-hour average PM2.5 concentration for the 2013-15 period. Historically, the ALA has screened out data collected by the Hoopa Valley Tribal EPA during the 2014/15 time period, as it does not meet quality assurance criteria (i.e. collected with an instrument not meeting quality assurance requirements). Unfortunately, this year the screening step appears to have been missed. If the unqualified data is not included, Humboldt County again receives an “A” for High Particle Pollution Days. Staff has advised the ALA and will work with them to ensure this particular error is not repeated in next year’s report.

A key point to note in regards to the ALA grade/report is that the grade represents a much more conservative and restrictive methodology which uses AQI (Air Quality Index) for reporting daily air quality. This is separate from the existing health-based state and federal ambient air quality standards (AAQS) and assessment basis for attainment designations. Because the ALA report bases its grades in part on the AQI, rather than the AAQS, it is possible to receive an “F” on the report, while still meeting all the AAQS requirements. In the future as other monitors are deployed and report data in our area, the ALA grade for Humboldt County could indeed change to a “C” or other grade.