Allergy Handbook

Allergy and The Environment – An Arizona Handbook

The Arizona Allergy and Asthma Society is an organization comprised of board-certified and board-elligible Allergy/Immunology specialists in Arizona. One of our goals is to serve as a resource for allergy information to the Arizona public. This is achieved by providing Arizonians with the “Allergy and the Environment, An Arizona Handbook.” On online version of this handbook is available below.


How do I reduce exposure to pollens?


by Suresh C. Anand, M.D.

Approximately 80 percent of allergies are caused by inhalants such as pollens, molds, animal dander, and house dust mites.

Pollens are difficult to avoid because they are in the air. Plants which cause allergies usually produce light pollen grains which are wind borne (not insect borne). In order to survive, these plants are prolific and produce massive amounts of pollen, which can travel hundreds of miles. In most parts of the country, trees pollinate in the spring, grasses in summer, and weeds in the fall. In Arizona, due to warmer weather, we have long pollen seasons, almost all year around. Also, we have two weed seasons—spring and fall!!

The following guidelines will reduce pollen exposure:

  • Stay indoors during the high pollen season. Keep doors and windows closed.
  • Central air conditioning is better than evaporative cooling. Avoid window fans or attic fans which can draw pollen into homes. Exhaust fans can be helpful.
  • A good air filter on a central air conditioning system, or a portable filtering until in the bedroom, can be helpful. Use a HEPA (High Energy Particulate Air) filter, or an electrostatic precipitator.
  • Keep car windows closed; use air conditioner on “recirculate” while driving.
  • If possible, let someone else do the outside mowing, sweeping, raking, etc.
  • Wear a good dust mask when mowing the lawn or doing outside work. Take allergy medicine beforehand if possible. Take a shower to wash off any pollen in the hair or on the body. Wear fresh clothes.
  • Don’t hang clothes or bedding outside to dry. They are good pollen catchers.
  • There is increased pollen and mold in the air between 5 and 10 AM. Limit outside activities in early morning. In Arizona certain air conditioned shopping malls are open early in the morning, for people who walk for exercise.
  • Plan your vacations during high pollen seasons and go to a place where, hopefully, there is less pollen to which you are allergic. Talk to your allergist before making such plans.
  • Ask your doctor for medicines which will prevent or decrease allergy symptoms.

What are the aeroallergens in Tucson?


by Kundagal Murthy, M.D.

If you were allergic to pollen before coming to Tucson, the chances are your allergies became worse after your move. The incidence of allergies in Tucson is about twice the average incidence for our country. Even by conservative estimates it appears that one person out of every five has allergic symptoms. The increased incidence of allergies can be attributed to the increased pollen from trees, weeds, and grasses.

Tucson is one of the very few places where records of pollen counts have been kept for many years. The records over the five decades starting in the 1940s indicate that the pollen counts have increased disproportionately to the increase in population. This increase is due to the fact that plants were brought to this desert from other parts of the country, and also to the landscaping preferences of the people. Native ragweed and other weeds have also contributed to the problem. Mild temperatures and sunshine throughout the year encourage the growth of plants, resulting in increased production of pollen.

Tree pollens of significance include junipers arriving as early as January, ash and cottonwood in January to February (the “cotton” flying in the air in spring is not the allergen), mulberry in March, olive in April, and later privet and mesquite. Tamarisk (salt cedar) pollinates in summer, and Rhus lancia (African sumac—which has not been well studied) in the fall.

Bermuda grass and Johnson grass pollens (the latter growing in ditches by roads, and not a heavy pollen producer) are noted in April and May and continue through the summer. Canyon ragweed pollinates in spring and fall. Rabbitbush, another ragweed, pollinates in spring. With fall come more weed pollens: Russian thistle (tumbleweed), pigweed, saltbush, and lamb’s quarters.

Molds are present year round but peak outdoors in late summer and fall. Some mold spores are present after heavy summer rains, others on dry, windy days.

Because of the continued increase in pollen counts of grasses, trees, and weeds over the years, Pima County enacted an ordinance in January 1995, to control and reduce the large amounts of allergenic wind-born pollen that cause human disease. It allows for enforcement of mandatory cutting of Bermuda grass, and prohibits the sale and planting of mulberry and olive trees in Pima County. Since the ordinance was enacted, counts of Bermuda grass, mulberry, and olive tree pollens have fallen.

Spring and fall are the two major seasons for severe allergy problems. However, a person allergic to grass pollen may have symptoms almost throughout the year.

What are the aeroallergens in Southeastern Arizona?


by Reuben G. Wagelie, M.D.

The Physical Geography of Southeastern Arizona’s basin and range consists of wide valleys and mountains ranging from 3,000 to 10,000 feet in elevation. The soil varies from deep fine-textured to rocky shallow soils in the mountains. Precipitation varies from 10 to 35 inches per year. These factors, for the most part, determine the quality and the quantity of the vegetation.

The major communities in this area include Benson, Sonoita, Patagonia, Sierra Vista, Nogales, Bisbee, Douglas, Willcox, Safford, and the Clifton-Morenci area. A pollen survey conducted by the Environmental Sciences Services Administration in Fort Huachuca identified the predominant allergens.


Pollens from trees dominate the spring months. In high elevations, mountain cedar, cottonwood, and junipers pollinate as early as January, followed by other trees indigenous to the area. This includes mulberry, ash, elm, mesquite, and walnut and oak at higher elevations. Water-dependent trees such as sycamore and cottonwood are found in the arroyos. Cottonwoods are the dominant trees along the banks of the San Pedro River. The pecan groves along the Santa Cruz River, not only in the Southeastern Basin but also in the Central Arizona Basin, contribute to the spring problems.


Bermuda is the dominant grass. It is equally important in the higher elevations as it is in the Central Basin.

The desert grassland areas are on the rolling and hilly outwash slopes at elevations from 3,000 to 5,000 feet. Grama grass, Lehman’s love grass, and sprangletop grass were identified. While these grasses pollinate in late spring and summer, Bermuda and Johnson continue through fall.


Giant ragweed (ambrosia), familiar to those who used to reside in the East or the Midwest, in not common. Other weeds, some referred to as false ragweeds, are found, including rabbitbush, slender ragweed, bursage, careless weed, saltbush, and tumbleweed.


The pollen and mold survey also indicated the presence of molds almost through the year. The Willcox and the Thatcher-Safford areas are basically ranching and agricultural communities. Molds commonly isolated were Alternaria, Cladosporium, and Helminthosporium.

Are there allergens specific to other towns in Arizona?


by Geraldine Freeman, M.D.

The many small rural towns in Arizona vary by location and elevation. Several still have working copper smelters (whose sulfur dioxide pollutant output has been reduced by technological improvements); there are coal-burning plants in the Four Corners area, St. Johns, Joseph City, and Page. These are monitored by the Arizona Department of Environmental Quality and are much improved in air quality.

Riparian (river bed) growth of mesquite, tamarisk (salt cedar), cottonwood, and sycamore is abundant. Mulberry trees, planted throughout the state for shade up to 5,000 feet elevation, produce pollen in spring. Areas of juniper produce significant pollen problems from December to early spring. Pine pollen is seldom allergenic.

Bermuda grass, both in lawns and escaped from cultivation, thrives up to 5,000 feet elevation. Sagebrush is found on the Colorado River plateau in northeastern high country. The desert type is Sonoran, featuring mesquite, palo verde, and non-allergenic cacti.

Ajo. Small desert community at 1,500 feet elevation in southwestern Arizona. Previously a copper town, now largely a retirement community. Native plants include desert ragweeds, pigweed, saltbushes, cottonwood trees, mesquite, and ironwood. Imported plants include mulberry, pepper, olive, and juniper trees, and Bermuda grass.

Casa Grande. Low desert agricultural community and commerce center one hour south of Phoenix. Agricultural products include cotton, alfalfa, wheat, and sorghum; there is a cotton gin in nearby Coolidge. Native plants include ragweeds, saltbushes, pigweed, tumbleweed, mesquite, cottonwood, tamarisk (salt cedar), and Johnson grass. Bermuda grass and elm, mulberry, and a few olive trees are planted in the town.

Colorado River Basin. Parker, at 450 feet elevation, grows alfalfa year round, and features Bermuda grass and a variety of weeds, native cottonwoods and mesquite, and planted mulberry and olive trees. Lake Havasu City, at 500 feet, has Bermuda grass (including golf courses), weeds, and pepper and smoke trees. Both areas are known for water recreation on the Colorado River in west central Arizona.

Cottonwood and Camp Verde. Featuring riparian growth along the Verde River, at 3,200 to 3,500 feet in central Arizona. Juniper is common. Camp Verde has pecan orchards; both areas have Bermuda and blue grass, a variety of weeds including saltbush and tumbleweed, nettles, and elm trees. Ailanthus (tree of heaven), ash, oak, and pine trees grow in nearby Jerome, at 5,000 feet.

Globe-Miami. At 3,500 feet, middle chaparral desert in central Arizona, with copper mines and smelter. Desert ragweeds, saltbushes, pigweed, tumbleweeds, box elder, cottonwood, elm, junipers, and ailanthus (tree of heaven) are native. Kentucky blue and Bermuda grass, and mulberry trees, are planted. The surrounding country grows juniper and oak; nearby canyons support a variety of trees.

Grand Canyon. The South Rim visitor area, at 6,000 feet elevation 90 miles northwest of Flagstaff, is in mixed oak-pine-juniper forest, with sagebrush and other weeds and wild grasses.

Kingman. 3,300 feet elevation in northwestern Arizona. Imported plants include Bermuda and Kentucky blue grass, and mulberry and other trees. Natives plants include ragweeds, pigweed, tumbleweed, saltbushes, cottonwood, junipers, and mesquite. Utah juniper grows in the nearby mountains.

Navajo and Hopi Reservations. Large, sparsely-occupied territory in the northeastern part of the state, much of it at 6,000 feet or higher. A variety of grasses, and often juniper, grow on this high desert plateau. Willows are planted for shade in some communities. There is open-pit coal mining in operation.

Page. A small community at 4,300 feet on Lake Powell, on the Arizona-Utah border. A coal-burning plant, hydroelectric power generation, and recreation on the lake and Colorado River. There are lawns of Bermuda, blue, rye, and fescue grass. The great variety of planted trees includes Russian olive (not a true olive). Sagebrush and rabbitbrush are natives.

Payson. 5,100 feet in east central Arizona, popular for retirement. Located in juniper-oak-pinion pine forest, with a variety of grasses, weeds, and ash and box elder trees.

Prescott. In juniper forest at 5,200 feet in the central Arizona mountains. There is a variety of weeds, lawn and wild grasses including Johnson grass, and trees including elm, box elder, cottonwood, oak, mesquite, mulberry, sycamore, and Russian olive.

Sedona. On Oak Creek, at 4,500 feet in central Arizona. Normal riparian growth, with hardwoods (alder, maple, black walnut, ash) in the upper canyon. The forest is heavily juniper and the related Arizona cypress, and sycamores near the creek in open terrain and near the town. Bermuda, blue, and wild grasses; mesquite, cottonwood, and a variety of weeds.

White Mountains. Show Low, Lakeside, Pinetop, and Springerville are located at 6,300 to 7,000 feet in the mountains of east central Arizona. There is a variety of wild and pasture grasses, pine-oak-juniper-aspen forests, agriculture and cattle, sagebrush and weeds. Some riparian areas—the source of the Little Colorado River.

Winslow. 4,800 feet, 60 miles east of Flagstaff in east central Arizona. A rural town in the Little Colorado River basin, along Interstate 40, previously a railroad center. Bermuda, blue, and wild grasses; various planted and wild trees (ash, box elder, elm, tamarisk, cottonwood, juniper, poplar, Russian olive, willow) and weeds (pigweed, ragweeds, tumbleweed, and sagebrush).

Yuma. A small, growing city in southwestern Arizona, at 200 feet elevation, on the Colorado River. There are citrus groves, farming, a Marine base, and Bermuda grass farms and lawns in the area. Olive, mulberry, privet, pecan, willow, and ash trees are planted here, and mesquite, tamarsk, and cottonwood are native. Low desert weeds appear in the spring and fall.

What are airborne irritants?


by J. Christopher Lewis, M.D.

The air we breathe is a mixture of gases and particles. These substances, as well as the temperature and humidity of the air, can affect the mucus membranes of the body’s eyes, nasal passages, and bronchial tubes. We may categorize airborne substances as falling into one of two broad categories: aeroallergens and irritants. Aeroallergens (airborne allergens) include pollens from trees, weeds, and grasses, molds, insect parts, and animal proteins. Irritant substances include dusts and smokes of any type, strong odors, fresh newsprint, soot, sulfur dioxide, photochemical smog, et cetera. While only allergic individuals will be bothered by exposure to the airborne allergens, anyone could be troubled by exposure to an irritant depending on how high the concentration is. Just as some people have sensitive skin, other have sensitive mucus membranes that are very easily irritated. Many individuals are bothered by both aeroallergens and irritants.

People sensitive to irritants should try to avoid known irritants whenever possible. Proper ventilation and filtration are important in reducing irritant levels. One should try to prevent dust accumulation and to avoid heavy dust exposure where possible. If avoidance is not possible, then a mask should be worn to reduce the personal exposure level.

It is important to check and clean or replace the filters on heating and air conditioning systems regularly. Air purifiers are available as freestanding units. If employed, it is important to get a purifier that is powerful enough to clean the air in the room in which it will be used, and it should be of a HEPA type, which is a high- efficiency particle removing system. Air purifiers which produce ozone are not recommended, as ozone is a respiratory irritant.

Some of the same medicines that are used to treat airborne allergy symptoms may be used to treat symptoms in patients who are sensitive to airborne irritants. In general terms, the response to the medications to control the reaction to irritants is not as dramatic as it is in those with allergy related symptoms.

Allergy and the Environment