School officials desperate to calm worried parents bought these devices and others with a flood of federal funds, installing them in more than 2,000 schools across 44 states, a KHN investigation found. They use the same technology — ionization, plasma and dry hydrogen peroxide — that the Lancet COVID-19 Commission recently deemed “often unproven” and potential sources of pollution themselves.
Aerosols—particles of hydrocarbons referred to as PM2.5 because they are smaller than 2.5 microns in diameter and easily lodge in the lungs—are proven to cause cardiovascular and respiratory problems.
As a result of strict vehicle emissions laws, organic aerosol levels have been significantly reduced throughout the United States, but the drop has been particularly dramatic in Los Angeles, which started out at a higher level.
Based on pollution measurements over the past 20 years, the UC Berkeley scientists found that concentrations of PM2.5 in the Los Angeles basin in 2012 were half what they were in 1999. As a result, from 2016 to 2018, there were almost no PM2.5 violations in the area when temperatures were low, below 68 degrees Fahrenheit. But at warmer temperatures, aerosol concentrations rose—over the same time period, 70% to 80% of days over 100 F exceeded the National Ambient Air Quality Standard (NAAQS) threshold.
Weird but fascinating article about how Los Angeles choice of palm trees may be effecting ozone levels on hot days. That said, color me skeptical as there are still a lot of tailpipes in a unique air basin that traps in pollution.
People traveling on subway systems in major US cities are being exposed to unsafe amounts of air pollution, with commuters in New York and New Jersey subjected to the highest levels of pollution, research has found.
Tiny airborne particles, probably thrown up by train brakes or the friction between train wheels and rails, are rife in the 71 underground stations sampled by researchers during morning and evening rush hours in Boston, New York City, Philadelphia and Washington DC, the cities that contain the bulk of subway systems in the US.
The Outdoor Air Quality - Fine Particulate Matter data available on CDC WONDER are geographically aggregated daily measures of fine particulate matter in the outdoor air, spanning the years 2003-2011. PM2.5 particles are air pollutants with an aerodynamic diameter less than 2.5 micrometers. Reported measures are the daily measure of fine particulate matter in micrograms per cubic meter (PM2.5) (µg/m³), the number of observations, minimum and maximum range value, and standard deviation. Data are available by place (combined 48 contiguous states plus the District of Columbia, region, division, state, county), time (year, month, day) and specified fine particulate matter (µg/m³)value. County-level and higher data are aggregated from 10 kilometer square spatial resolution grids.
https://wonder.cdc.gov/controller/datarequest/D73
The American Lung Association’s annual report card on air quality found more U.S. cities and more people experienced unhealthy air than in the previous report. And it ranked the Philadelphia and Pittsburgh areas as among the most polluted in the country.
The association says its 2020 State of the Air report provides more evidence that climate change is making it harder to protect human health.