Pollen and Mold Summary 2010
Unlike the other pollutants for which RAPCA runs monitors, pollen and mold are
unregulated. There is no NAAQS (standard) for either pollen or mold. We
maintain the monitor due to our curiosity and the great public interest in these
biological pollutants. If we are not affected ourselves, we all know someone who's
miserable during the appropriate pollen and/or mold season.
Although unregulated per se, pollens and molds can contribute to the regulated
pollutant called particulate matter (PM), in particular, to PM10 and PM2.5. In most
cases, however, the pollen grains are even bigger than 10 microns and will tend to
be omitted by even the PM10 samplers. Molds can be small enough to be collected
in with the PM10 data, but in many cases the molds cluster together to form
aggregate particles which are also bigger than 10 microns.
Pollen
Pollen is the name for the small, spherical, or egg-shaped grains which are
produced by plants, flowers, weeds, grasses, and trees, and are necessary for plant
fertilization. When ingested or inhaled, pollen can trigger allergic reactions,
ranging from mild to severe, in about 40 million Americans.
There are two basic types of pollen, those that are carried by insects and those that
are carried by the wind. The latter type of pollen is the type which is most often the
culprit in allergies. Most flowers, such as roses and even goldenrod, produce
pollen which is carried by insects. In contrast, grasses, weeds and trees produce
small, light grains of pollen which are easily transported by the wind.
Hay fever, the body's allergic reaction to pollen, is the most common allergic
disease in the United States. Hay fever is characterized by nose, eye and throat
irritation, including sneezing, congestion, coughing and difficulty in breathing.
One in three hay fever sufferers develops asthma, a serious respiratory disease.
Mold
Mold spores are fungal reproductive cells of about the same size as pollen grains.
They can occur in various colors and shapes, such as round, spheroid, bananashaped, or tadpole-shaped. They can occur in enormous quantities, and at all times
of the year. Furthermore, they can cause allergic rhinitis (like hay fever), skin
reactions, and possibly asthma. During the fall harvest season incredible amounts
of molds can be stirred up, but well isolated from large populations, fortunately.
Mold spores can be found and generated at serious levels indoors, as well as out.
Stachybotrys chartarum, sometimes called “black mold”, for example, has been in
the news when found in large quantities in indoor air. It produces toxins harmful
to humans.
RAPCA informs local radio and television stations as well as the newspaper. The
total counts for pollen and mold are also available daily on RAPCA's AirLine at
223-3222 (after 4:00 p.m.) and a more detailed report is available as well from
RAPCA's web page at http://www.rapca.org/daily/aqstats.htm. People with special
requests should contact RAPCA by phone.
The Monitoring Technique
Monday through Friday, RAPCA collects samples in the morning at our monitor
on the roof of the Dayton-Montgomery County Library on E. Third & St. Clair
(RAPCA Site # 46).
RAPCA uses a Burkard 7-day Recording Volumetric Spore Trap courtesy of the
American Academy of Allergy, Asthma, and Immunology (AAAAI) and their
National Allergy Bureau (NAB).
This sampling unit sucks particles inside where they run head on into a "greased"
microscope slide and are captured. The slide is slowly pulled past the intake orifice
so that readings by time of day can be developed, not that we have the time for this
maneuver!
After exposure, the slides are removed and stained with a red dye solution before
counting under an optical microscope. Separate speciation is made for numerous
pollen and mold types. Pollen species are then grouped into broader concentrations
for grass, trees, weeds, and "other”.
Because the intake flow rate is a constant value, the volume of air drawn in can be
computed. The pollen or mold counts from the microscope slide can then be
divided by the volume of air to give a concentration, the number of particles per
cubic meter (p/m3).
Our detailed data are sent to the American Academy of Allergy, Asthma, and
Immunology for inclusion in their daily web-based Pollen and Spore Reports. In
addition, we continue to report the data daily on our web site and send it to the
local media.
2010 Data
The summary tables for the pollen and mold data can be found in an Excel (.XLS)
spreadsheet at raw pollen & mold data, or as a simple HTML table, and the table
common names for pollen species may make things a bit more understandable. If
you need the day-by-day tables, please contact us, but first look at the Air Quality
Reports on our web site, www.rapca.org.
Pollen Discussion
Trees dominate our pollen readings, primarily in the early spring. In 2010 the
highest emitters were quercus (oak), morus (mulberry), salix (willow),
cupressaceae (cypress etc.), and ulmus (elm).
Although there is a “grass season” between trees and weeds, grass concentrations
are much lower than either of the other two groups.
The following tables should help illustrate these points.
@@@@All charts done, but text only to right here
Year 2010 Pollen Graphs
The three main pollen seasons are shown in the 3 graphs below. First comes the
tree pollen, then grasses, and finally flowers, weeds, etc. Trees dominate the spring
and ragweed dominates the fall. Notice the change in scale needed to show the
high tree pollen concentrations.
Trees, Grass, & Weeds
A look at the raw data tables will show you that most of the weed pollen is composed of ragweed
(ambrosia in the tables.) Traditionally, ragweed peaks on Labor Day.
Ragweed levels in 2009 were nothing extraordinary.
2009 Mold Discussion
Cladosporium rules! The single highest daily concentration for any mold species was
34,637 for cladosporium, followed in second place by only 15,026 for ascospores.
Cladosporium also had far more total spores spread throughout the year than any other
mold, even ascospores. Some years, however, there can be more total ascospores. Both
types occur on most days of the year.
Year 2009 Mold Graphs
Total Mold
Comparisons of 2009 and other years:
Please remember that the monitoring location changed from Centerville to Dayton
in mid-2001, so you will still be looking at "apples to oranges" comparisons.
Also, please bear in mind the large year-to-year variation you will see in the
following two graphs if you ever feel impelled to assert that “this year was an
unusually bad year for mold.”