STOP: TULE FOG
LISTEN/DOWNLOAD [MP3]
SB CUE Panoche Road
NB CUE Panoche Road
SITE
Tule Fog
View LANDSAT Map
LOCATION
San Joaquin Air Basin
THREATS AND CONTAMINANTS
Diesel emission particles (DEP), ammonia, methane, pesticides, herbicides, and other particulate matter (PM) trapped in fog
VOICE
Dr. David Pepper, Department of Family and Community Medicine UCSF
Between November and March, Tule Fog can sit for days over large swaths of the San Joaquin Valley. During Tule Fog, visibility is uneven and can drop rapidly while driving, from 600 feet to as little as ten feet. In December 1997, five people died and twenty-eight were injured when twenty-five cars and twelve big rig trucks collided inside a fog bank on I-5 south of Sacramento.
Tule Fog is a type of radiation fog created when the earth's surface cools air near the ground to a temperature at or below its dewpoint, usually at night or in the early morning, and when the ground is moist or wet. Air pollutants are hygroscopic, readily absorbing moisture, and can act as condensation nuclei, causing the fog to be comprised of small droplets, rather than large droplets, resulting in denser fog, similar to that of industrial-era London. High concentrations of particulate matter from diesel exhaust, ammonia from dairying, incineration, and other pollution sources in the Valley help fog form more easily, and may make Tule Fog more frequent.
Fog particles can absorb higher concentrations of pollutants than the surrounding air, and contaminated fog may pose a greater health threat than contaminated air because the concentrated pollutant particles in fog stay in the lungs. The smallest particles are particularly dangerous. They get transported down into the lungs and across into the blood, causing acute irritation and inflammation in the lungs, as asthma, and long-term disease, like emphysema, bronchitis, lung cancer, heart disease, and strokes. James N. Siebert, an environmental toxicologist, identified sixteen different pesticides in Tule Fog.
In findings from the 2003-2005 Sacramento / Interstate-5 Aerosol Transect Study, the I-5 "was identified as a major source of the fine particulate pollution... with roughly one-third attributable to diesel particulates and smoke-producing gasoline cars. It was also determined that at certain times and under certain conditions, particulate pollution in Sacramento comes up on slow winds from the San Joaquin Valley. These particulates travel parallel to Hwy. 99 and I-5, and produced the worst air quality at the monitoring sites..."
LISTEN/DOWNLOAD [MP3]
SB CUE Panoche Road
NB CUE Panoche Road
SITE
Tule Fog
View LANDSAT Map
LOCATION
San Joaquin Air Basin
THREATS AND CONTAMINANTS
Diesel emission particles (DEP), ammonia, methane, pesticides, herbicides, and other particulate matter (PM) trapped in fog
VOICE
Dr. David Pepper, Department of Family and Community Medicine UCSF
Between November and March, Tule Fog can sit for days over large swaths of the San Joaquin Valley. During Tule Fog, visibility is uneven and can drop rapidly while driving, from 600 feet to as little as ten feet. In December 1997, five people died and twenty-eight were injured when twenty-five cars and twelve big rig trucks collided inside a fog bank on I-5 south of Sacramento.
Tule Fog is a type of radiation fog created when the earth's surface cools air near the ground to a temperature at or below its dewpoint, usually at night or in the early morning, and when the ground is moist or wet. Air pollutants are hygroscopic, readily absorbing moisture, and can act as condensation nuclei, causing the fog to be comprised of small droplets, rather than large droplets, resulting in denser fog, similar to that of industrial-era London. High concentrations of particulate matter from diesel exhaust, ammonia from dairying, incineration, and other pollution sources in the Valley help fog form more easily, and may make Tule Fog more frequent.
Fog particles can absorb higher concentrations of pollutants than the surrounding air, and contaminated fog may pose a greater health threat than contaminated air because the concentrated pollutant particles in fog stay in the lungs. The smallest particles are particularly dangerous. They get transported down into the lungs and across into the blood, causing acute irritation and inflammation in the lungs, as asthma, and long-term disease, like emphysema, bronchitis, lung cancer, heart disease, and strokes. James N. Siebert, an environmental toxicologist, identified sixteen different pesticides in Tule Fog.
In findings from the 2003-2005 Sacramento / Interstate-5 Aerosol Transect Study, the I-5 "was identified as a major source of the fine particulate pollution... with roughly one-third attributable to diesel particulates and smoke-producing gasoline cars. It was also determined that at certain times and under certain conditions, particulate pollution in Sacramento comes up on slow winds from the San Joaquin Valley. These particulates travel parallel to Hwy. 99 and I-5, and produced the worst air quality at the monitoring sites..."
