New Orleans Area Environmental Quality Test Results

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New Orleans Area Environmental Quality Test Results

http://www.nrdc.org/health/effects/katrinadata/mold.asp

Mold

NRDC sampled for mold in October and November, 2005.

Health Effects of Mold

Mold is the common name used to describe various types of fungus

that can be found growing both indoors and outdoors, especially in

moist warm environments. Exposure to mold in outdoor air can cause a

number of health effects including allergic reactions, asthma

attacks, and even infections in people with immune system problems.

Mold can be a dangerous indoor air contaminant and its presence in

residential and occupational settings usually requires prompt

attention and cleanup.

Mold growing on damp surfaces releases spores that become airborne

and can be inhaled, leading to a host of respiratory problems. Some

molds also produce chemicals (mycotoxins) that may be toxic to

humans if inhaled. Mold exposure can cause congestion, sneezing,

runny or itchy nose, and throat irritation; more serious symptoms

include major allergic attacks, cough, asthma attacks, and

hypersensitivity pneumonitis (a pneumonia-like illness with symptoms

including difficulty breathing and fevers). Some studies have shown

that outdoor levels of mold spores are directly associated with

childhood asthma attacks requiring a visit to an emergency room.

Studies that have reported links between outdoor mold spore levels

and childhood asthma attacks have found these respiratory effects

even in areas where the daily airborne spore counts were relatively

low (around 2,000 spores per cubic meter). Mold in the home

environment has been extensively studied. The National Academy of

Sciences has concluded that there is sufficient evidence of a causal

link between indoor mold and the following health effects: nose and

throat symptoms, coughing, wheezing, asthma symptoms in sensitized

people, and hypersensitivity pneumonitis in susceptible people.

Some people have reported a wide range of other symptoms associated

with mold exposure -- including headache, difficulty concentrating,

memory loss, skin rashes, diarrhea, and pulmonary hemorrhage in

infants -- but these health problems are currently less well-

established scientifically. Invasive fungal pneumonia almost never

occurs in healthy people, but can be a very serious threat to people

with weak immune or lung function. The long term effects of exposure

to mycotoxins in humans are unknown and remain of high concern.

The health hazard posed by mold is usually assessed through a

description of the quantity of fungal spores and a description of

the different types of mold present. It is generally accepted that

increasing levels of airborne spores represent an increased health

risk and spore counts in problem areas are often compared to

background levels. Of the thousands of types of molds found in

indoor and outdoor environments, adverse health effects associated

with spores from species of Alternaria, Aspergillus, Cladosporium,

Penicillium, and Stachybotrys have been well documented.

There are no U.S. regulatory standards for either indoor or outdoor

levels of mold spores in the air. In the indoor environment, the

standard practice is to compare the mold concentrations, and the

specific types of mold present, with outdoor concentrations at the

same location. If the indoor levels are higher, or if the dominant

mold species are significantly different, that indoor environment is

considered to have a mold problem that requires attention. Some

organizations have set more specific cut-offs for mold in the

environment. The National Allergy Bureau of the American Academy of

Allergy and Immunology has set general nationwide definitions for

mold spore counts in the outdoor environment (see Table 1). These

guidelines are especially useful for people with allergies, asthma,

or other respiratory conditions. Various organizations have set

definitions for mold concentrations in indoor air. However, in most

cases these use a different measurement method, colony-forming units

instead of spores. One colony-forming unit originates from one

living spore; however, both living and dead spores may produce

undesirable health effects. Colony-forming units are difficult to

compare with spore counts. However, some authors have recently

devised criteria for cut-offs to differentiate " clean " from " moldy "

residential buildings. These criteria are presented in Table 2.

Table 1

National Allergy Bureau Outdoor Mold Counts

0 Absent

1-6,499 Low

6,500-12,999 Moderate

13,000-49,999 High

> 50,000 Very High

Note: numbers are in daily average spore counts per cubic meter

Source: American Academy of Allergy and Immunology

http://www.aaaai.org/nab/index.cfm?p=reading_charts

Table 2

Indoor Mold Classifications: Residential Buildings

Total Spores

< 1,200 - Clean

> 1,300 - Moldy

Aspergillus/Penicillium

< 750 - Clean

> 900 - Moldy

Ascospores/Basidiospores

< 1,200 - Clean

> 1,300 - Moldy

Note: numbers are in spores per cubic meter

Source: Baxter et al. J Occup Environ Hygiene, 2005

How We Sampled for Mold

We collected air samples for mold spore analysis at two different

times in a total of 17 outdoor locations spread across the New

Orleans area, including Uptown/Carrollton, Mid-City, the French

Quarter, Lakeview, Gentilly, the Lower Ninth Ward, Bywater, New

Orleans East, Chalmette, Metairie and Mandeville. Twelve of these

locations had been significantly flooded; two were near flooded

areas but were not themselves flooded; and three were in areas

further from the flooding. We also sampled in eight indoor locations

(in Broadmoor, Mid-City, Lakeview, the Lower Ninth Ward and New

Orleans East). All of the indoor locations had been flooded, but

some had been partially remediated. Our sampling was done from

October 17-19 and November 13-16, 2005.

We collected continuous volumetric samples using a Burkard

Continuous Recording Air Sampler with a flow rate of 10 liters per

minute for 6 to 24 hours. The results were extrapolated to estimated

average 24-hour mold spore concentrations expressed as spores per

cubic meter of air. The instrument has greater than 90 percent

removal efficiency of particles with an aerodynamic diameter of 5 µm

and above. Fungal spores were counted and identified by Dr. Mervi

Hjelmroos-Koski of INSTAAR, University of Colorado at Boulder.

Results of Mold Sampling

The levels of mold spores in the air in New Orleans were extremely

high, and could pose a serious health threat especially to anyone

who is allergic to molds, and to people with asthma and other

respiratory disease. We found elevated levels of mold spores both

inside homes and outside, especially in flooded areas.

Outdoor Air

Our testing revealed a significant mold problem in outdoor air in

most of the flooded areas of the city. Mold spore counts in most

flooded neighborhoods -- including New Orleans East, the Lower Ninth

Ward, Bywater, Gentilly, Chalmette, Uptown/Carrollton and Mid-City --

were classified as " Very High, " with estimated average daily spore

counts over 50,000 spores per cubic meter. Levels in Lakeview

were " High, " according to the standard classifications of the

National Allergy Bureau. These outdoor mold spore concentrations

could easily trigger allergic or asthmatic reactions in sensitive

people. Our sampling in the French Quarter and Uptown in streets

that were not flooded also showed high levels of mold, but these

areas are close to flooded areas and mold spores are known to travel

significant distances in the air. In contrast, more distant

comparison sites in Metairie and in Mandeville on the north shore of

Lake Pontchartrain had significantly lower mold spore

concentrations. Figure 1 shows the average spore concentrations at

12 outdoor sites in the flooded areas of Orleans and St. Bernard

Parishes compared to the average spore concentrations at two sites

in areas of Orleans Parish that were not directly flooded (the

French Quarter and part of Uptown). The third column represents two

samples taken in Metairie, Jefferson Parish, further upwind of the

flooded areas and one sample taken on the north shore of Lake

Pontchartrain in a non-flooded area.

Figure 1

Indoor Air

Mold spore levels were extremely high in the flooded and not yet

remediated indoor location we tested (moldy furniture, carpets and

drywall still in place). This home had mold spore concentrations of

650,000 spores per cubic meter (spores/m3), which would render it

dangerously uninhabitable by any definition. We tested three homes

that had undergone some remediation (removal of contaminated

furniture and carpets, some removal of drywall). These had average

mold spore concentrations of 377,000 spores/m3, which was still

dangerously high. Two of the homes we tested had been fully

remediated (removal of all furniture, carpets and drywall down to

the studs, airing and mold treatment). These homes had average mold

spore counts of 72,000 spores/m3, which was nearly the same as the

outdoor air at the same locations. Two homes in Leonidas (Uptown)

and Bayout St. (Mid-City) that had suffered only minimal

flooding (flooding of the crawl space, or less than three inches of

water for a brief period in the living space) averaged only 11,000

spores/m3 in the indoor air, which was considerably lower than

outdoor air samples taken at the same locations.

Mold, Figure 2

By far the most common types of mold that were detected in our

sampling were Cladosporium and Aspergillus/Penicillium species.

Outdoors, in flooded areas, Cladosporium species accounted for about

20 percent to 50 percent of spores found, and

Aspergillus/Penicillium species comprised about 20 percent to 70

percent of spores at any given location. In combination, these two

species accounted for about 60 percent to 90 percent of all of the

spores found. In the non-flooded sites, the dominant species was

Cladosporium (70 percent to 75 percent), and Aspergillus/Penicillium

was far less common. These molds are known to cause respiratory

problems in humans, including allergy, asthma and infections (in

immunocompromised people or people with underlying lung disease). In

addition, some species of Aspergillus and Penicillium which are

typically found in damp indoor environments produce fungal toxins

(mycotoxins) that may contribute to both short-term and long-term

health effects. Indoors, in flooded homes, the dominant species was

Aspergillus/Penicillium, which comprised more than 70 percent of the

fungal spores. The fully remediated homes and less-flooded homes had

fungal spore distributions that were similar to those in the outdoor

air. However, in four of the flooded homes (including one of the

fully remediated homes) we also detected airborne spores of

Stachybotrys species, which is also known as " black mold " or " toxic

mold. " Stachybotrys is known to produce mycotoxins that can cause

flu-like symptoms and other respiratory problems. This is a highly

controversial type of mold that some researchers have associated

with a variety of neurological effects, immune suppression and with

infant pulmonary hemorrhage.

Based on our sampling results, people working in the flooded parts

of the city, especially if there is building or demolition work

going on nearby, and anyone entering any buildings, should be sure

to wear respiratory protection -- specifically, an N95 dust

mask/respirator. A regular dust mask or bandana is not sufficient to

protect against these levels of mold contamination.

Mold Results by Neighborhood

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References

Baxter DM, et al. A regional comparison of mold spore concentrations

outdoors and inside " clean " and " mold contaminated " southern

California buildings. Journal of Occupational and Environmental

Hygiene. 2:8-18, 2005.

CDC Mold Work Group. Mold Prevention Strategies and Possible Health

Effects in the Aftermath of Hurricanes Katrina and Rita. Centers for

Disease Control and Prevention (CDC). October 2005.

http://www.bt.cdc.gov/disasters/mold/report/

Dales RE, et al. Influence of ambient fungal spores on emergency

visits for asthma to a regional children's hospital. American

Journal of Respiratory and Critical Care Medicine. 162: 2087-2090,

2000.

Gots DE, et al. Indoor Health: Background levels of fungi. AIHA

Journal 64:427-438, 2003.

Institute of Medicine. Committee on Damp Indoor Spaces and Health.

Damp indoor spaces and health. Washington, DC: National Academies

Press; 2004. http://www/nap.edu/catalog/11011.html

McNeel SV and Kreutzer RA. Fungi and Indoor Air Quality. Health and

Environment Digest Vol 10, No.2 May/June 1996. California Department

of Health Services, EHIB. http://www.ehib.org/cma/html_entity.jsp?

bcc=papers & paper_key=FUNGI_INDOOR_1996

Salvaggio J and Seabury J. New Orleans Asthma: IV. Semiquantitative

airborne spore sampling, 1967-1968. Journal of Allergy and Clinical

Immunology. 48:82-95, 1971.

University of Minnesota Fungal Information.

http://www.dehs.umn.edu/iaq/fungus/