Air quality: Shifting winds make Lowell Fire behavior, smoke conditions ‘difficult to predict’ |

Air quality: Shifting winds make Lowell Fire behavior, smoke conditions ‘difficult to predict’

Smoke Tuesday morning from the fire looking towards Grass Valley from Wolf Mountai.
Submitted photo/Jim Heath |


Nevada, Sierra and Plumas County (For July 28-31)

The Northern Sierra Air Quality Management District, in collaboration with Nevada County Public Health, is updating its air quality health advisory to include Wednesday through Friday, July 28 through 31, and also to include the potential for elevated ozone later in the week. Smoky conditions are likely to be experienced in parts of Nevada County due to smoke from the Lowell Fire in the Steephollow Creek area of southcentral Nevada County. At times, particularly later in the week, there could be smoke incursions into Sierra and Plumas counties as well.

Fire activity continues and dry, hot, windy conditions on Tuesday and Wednesday make fire behavior difficult to predict, especially considering the dense vegetation and rugged terrain of the fire area. Winds are forecast to be primarily out of the east on Tuesday and Tuesday night, which could carry smoke into western Nevada County and beyond. A shift to southwest winds on Wednesday is expected to move smoke across Nevada County, possibly reaching Truckee and eastern portions of Sierra and Plumas County. Wednesday through Friday, smoke may settle in low areas and the Bear River drainage at night, and then be carried to the northeast (across Nevada County again and possibly into Sierra and Plumas County) during the days. Also, smoke contains ozone precursor pollutants which easily react to form ozone in sunny, high temperature conditions, resulting in the potential for elevated ozone concentrations in western Nevada County Wednesday through Friday.

Smoke is primarily fine particulate matter less than 2.5 microns in diameter (PM 2.5), which can be inhaled deeply into the lungs. Smoke concentrations are expected to intermittently be in the Unhealthy for Sensitive Groups range and potentially reach or exceed the Unhealthy range over a wide area, and are expected to vary greatly during the course of each day depending on wind speed, wind direction, fire behavior and other factors.

Aggravation of heart or lung disease, severe breathing difficulty and premature mortality could occur in people with cardiopulmonary disease and older adults, while increased respiratory effects may be evident in the general population. People with heart or lung disease, older adults and children are especially sensitive to the health effects of smoke and should avoid physical activity outdoors. Everyone else should reduce prolonged or heavy exertion.

If you smell smoke, or see smoke around you, consider restricting your outside activities. Until the potential for poor air quality subsides, individuals should consider taking the following actions:

– Healthy people should delay strenuous exercise when they can smell and see smoke. That applies especially to school gym classes and athletic practices. Young athletes are considered sensitive individuals and any perceived benefits from a smoky workout could be outweighed by the negative impacts of the smoke inhaled during that workout.

– People with respiratory illnesses should remain indoors when smoke can be seen or smelled outside.

– People with asthma should follow their asthma management plan.

– Contact your doctor if you have symptoms such as chest pain, chest tightness, shortness of breath, or severe fatigue. This is important for not only people with chronic lung or heart disease, but also for individuals who have not been previously diagnosed with such illnesses. Smoke can “unmask” or produce symptoms of such diseases.

– If possible, sensitive individuals should consider relocating to another location that is not currently experiencing smoke impacts for a few days to avoid long term exposure.

– Keep airways moist by drinking lots of water. Breathing through a warm, wet washcloth can also help relieve dryness.

In general, when smoke concentrations are elevated it is advisable to stay indoors with windows and doors closed and set air-conditioners on “re-circulate.” Do not run swamp coolers or whole house fans. When feasible, pets should be brought indoors when outdoor air quality is poor. Warning: particulate respirators will not provide complete protection in very smoky conditions and may even interfere with proper breathing. It should also be noted that there is some controversy surrounding the use of particulate respirators because of the many variables that may hinder their proper use. Masks can create a false sense of security and should not replace reducing activity or exposure. If you need to wear a mask, wear the correct type of mask – disposable particulate respirators found at hardware stores can be effective at reducing exposure to smoke particles as long as they seal closely to the wearer’s face. Look for respirators that have two straps and have the words “NIOSH” and either “P100” or “N95” printed on the filter material.

Studies have linked fine particulate matter (smoke) with work and school absences, respiratory related hospital admissions and health problems, including burning eyes, aggravated asthma, acute respiratory symptoms (including severe chest pain, gasping, and aggravated coughing), chronic bronchitis, decreased lung function, and even premature death. Increased ozone exacerbates these health effects. In addition to the acute health effects of smoke, people may experience some cumulative effects, such as a dry cough and chest discomfort.

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