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Environmental Influences on Asthma. Steven R. Grandgeorge, MD Dartmouth Hitchcock - Manchester. Indoor Air Allergens. Most commonly identified sources of indoor allergens are: Dust mites Cockroaches Domestic pets Feral animal pests Fungi Plants and pollens Occupational.

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Environmental influences on asthma

Environmental Influences on Asthma

Steven R. Grandgeorge, MD

Dartmouth Hitchcock - Manchester


Indoor air allergens
Indoor Air Allergens

  • Most commonly identified sources of

    indoor allergens are:

    • Dust mites

    • Cockroaches

    • Domestic pets

    • Feral animal pests

    • Fungi

    • Plants and pollens

    • Occupational


Mold allergy
Mold Allergy

Mold can cause diverse health effects, related to the type of exposure and the unique characteristics of the individual

  • Allergic and other immunologic respiratory disease

    • 3.6% of general population test + for one or more molds

    • 22-38% of asthmatics test + for one or more molds

    • Approx. 50% of mold allergic patients express clinical disease

  • Mycotoxicosis

    • Documented with ingestion of contaminated foods

    • Airborne toxin has been detected with heavy industrial mold contamination

    • Not a concern in residential settings

    • NO “Toxic Mold Syndrome”

  • Infection

  • Aero-irritation

  • Psychogenic


Mold allergy home dampness
Mold Allergy: Home Dampness

  • Numerous studies of both adults and children in different countries have found a significant correlation between exposure to damp indoor environments (as evidenced by signs of mold growth) and the presence of various respiratory symptoms including cough, wheeze, rhinitis, and eye and nose irritation

  • Symptoms occur without regard to allergic status or to mold sensitization !


Mold allergy home dampness1
Mold Allergy: Home Dampness

  • Numerous studies of both adults and children in different countries have found a significant correlation between exposure to damp indoor environments (as evidenced by signs of mold growth) and the presence of various respiratory symptoms including cough, wheeze, rhinitis, and eye and nose irritation

  • Symptoms occur without regard to allergic status or to mold sensitization !

Aero-irritant effect


Mold allergy tri state homes
Mold Allergy: Tri-State Homes

  • Affordable prefabricated homes in Midwest US

  • 1960s-1970’s

  • Occupants noted:

    • Increased respiratory illnesses

    • Increased moisture

    • Mold growth in the homes

    • Premature decay of the structure


Mold allergy tri state homes1
Mold Allergy: Tri-State Homes

Wisconsin Department of Health and Social Services findings:

  • Compared environment and health of occupants of Tri-State Homes to that of a control group living in standard stick built homes

  • Tri-State residents had increased cough, phlegm, shortness of breath, nocturnal wheeze, stuffy nose, burning eyes and throat, and frequent colds

  • Homes had an impermeable, improperly placed vapor barrier


Mold allergy tri state homes2
Mold Allergy: Tri-State Homes

University of Wisconsin study findings:

  • High incidence of upper and lower respiratory irritation

  • Less than expected incidence of positive allergy tests to molds

  • Very high dust mite counts

  • Very high incidence of positive tests to dust mites


Mold allergy summary
Mold Allergy: Summary

  • There is relatively little research

  • There is NO “toxic mold syndrome”

  • As an indoor allergen, mold is considered a minor participant

  • Most who think they are allergic to mold are likely bothered by aero-irritants or other allergens (mites)

  • Mold may be a marker for poor indoor air quality


Dust mite allergy biology
Dust Mite Allergy: Biology

  • •Sources of house dust mite allergen

    • - Fecal matter and mite bodies are the major sources of allergen

  • Mites obtain and maintain water balance by absorbing water from the water vapor in air

  • Mite levels fluctuate relative to ambient humidity

Indoor humidity

Homes without A/C or dehumidifiers

Ave. live mites/g dust

(JACI 2001; 107: 99-104.)


Dust mite allergy distribution
Dust Mite Allergy: Distribution

Major mite breeding sites in homes:

Mite allergen in other locations:

  • Clothing: Small amts of live mites and allergens

  • Stuffed toys: Very low allergen levels

  • Offices: Usually low (occasional exception)

  • Schools: Usually low (occasional exception)

  • Churches: Low

  • Hotels: Significant amounts in beds

  • Hospitals: Low levels

  • Automobiles: Very low levels


Dust mite allergy distribution1
Dust Mite Allergy: Distribution

Mite allergen location in homes

  • Most mite allergen is associated with large dust particles that settle quickly (within 20-30 minutes)

  • Airborne allergen is low or non-existent in the absence of disturbance

  • Little allergen is found on vertical walls and tops of hard surface furniture

  • Little allergen on smooth surface floors if cleaned regularly


Pet allergens biology
Pet Allergens: Biology

Characteristics of pet allergens

  • Cat allergens

    • Secreted by sebaceous glands onto the skin and fur (also sublingual salivary glands and anal glands) and is under hormonal control

    • Secreted in copious amounts and accumulates in house dust

  • Dog allergens

    • Secreted by parotid gland and sebaceous glands

    • There is NO hypoallergenic dog; the breed of dog does not relate to the amount of allergen produced


Pet allergens distribution
Pet Allergens: Distribution

Differencesfrom dust mite allergens

  • Distributed on small particles that remain airborne for long periods

  • Airborne levels increase 5x when pet is in the room

  • Sticky; high levels found on walls and other surfaces

  • Clothing is an important means of distributing pet allergen to pet-free environments


Pet allergens distribution1
Pet Allergens: Distribution

National Survey of Allergens in Homes

  • Dog and cat allergens are detected in 100% and 99.9% of homes respectively

  • For dog, 34.9% exceeded the asthma symptom threshold level (9.3% of homes w/o dogs exceeded the threshold level)

  • For cat, 34.7% exceeded the asthma symptom threshold level (15.7% of homes w/o cat exceeded the threshold level)


Pet allergens distribution2
Pet Allergens: Distribution

Impact of school exposure

  • Pet allergen levels in schools are high enough to sensitize and to induce asthma symptoms

  • Increased symptoms, medication requirements, and risk of exacerbations has been correlated with high numbers of cat-owner classmates

  • Cat allergen levels in the homes of non-cat owner students correlate with cat allergen levels in schools


Allergen avoidance strategies
Allergen Avoidance Strategies

Relocation

Reservoir

removal

Allergen

avoidance

Air filtration

Source

removal


Allergen avoidance removal of biological sources
Allergen Avoidance: Removal of biological sources

Effect of Pet Removal on Pet Allergic Asthma

  • n=20 (10 removal; 10 keeping)

  • Follow-up ≥ 1 year

  • In the removal group:

    • Significantly greater

      improvement in BHR

    • Significantly lower

      ICS dosage

(Shirai et al. Chest 2005;127: 1565-71)


Allergen avoidance multi targeted approach
Allergen Avoidance:Multi-targeted approach

Results of a home-based environmental intervention among urban children with asthma (NEJM 2004; 351: 1068-80)

  • Interventions

    • Education

    • Impermeable mattress/pillow covers

    • HEPA-filtered vacuum

    • HEPA air filter

    • Professional cockroach extermination


Allergen avoidance multi targeted approach1
Allergen Avoidance:Multi-targeted approach

Results of a home-based environmental intervention among urban children with asthma (NEJM 2004; 351: 1068-80)

  • Results:

    • Decreased asthma

      symptoms

    • Reduction in disruption of

      caretaker activities

    • Decreased sleep loss

    • Decreased missed school

    • Decreased ED visits

      $1500 to 2000 / child / 2 years


Allergen avoidance multi targeted approach2
Allergen Avoidance:Multi-targeted approach

Results of a home-based environmental intervention among urban children with asthma (NEJM 2004; 351: 1068-80)

  • Results:

    • Decreased asthma

      symptoms

    • Reduction in disruption of

      caretaker activities

    • Decreased sleep loss

    • Decreased missed school

    • Decreased ED visits

      $1500 to 2000 / child / 2 years


Indoor air allergens assessing relevance
Indoor Air Allergens: Assessing Relevance

Allergic symptoms

+ Positive test

+ Exposure

“Relevant

allergen”

=


Are all allergens created equal
Are All Allergens Created Equal?

  • Response to allergens

  • may differ by:

  • Frequency of sensitization

  • Magnitude of IgE response

  • Exposure/sensitization relationship

  • Development of tolerance

Sensitization

Dust mite

Exposure

Cat

Sensitization

Exposure


Dermatophytes

Cockroaches*

Ladybugs

Helminths

Monkeys

Scabies

Reptiles

Grasses*

Humans

Rodents*

Fungi*

Trees*

Dogs*

Mites*

Birds

Cats*

Dinosaurs

Great Cretaceous

Catastrophe

X

80 Million

Mammals

300 Million

  • * Major inhalant allergen

  • * Allergens inducing tolerance

600 Million

1200 Million

1500 Million

The relevance of evolutionary distance to immunogenicity and cross-reactivity.


Avoidance of indoor allergens summary
Avoidance of Indoor Allergens: Summary

  • Identifying the important allergen(s) may be the key to success

  • Testing is required to reliably determine sensitivity to perennial indoor allergens

  • Studies of allergen avoidance measures have largely been disappointing

  • Individual avoidance measures are generally ineffective

  • Effective allergen avoidance requires a multifaceted, comprehensive approach





Air quality issues may be of particular concern for new englanders
Air quality issues may be of particular concern for New Englanders

New England lies directly downwind of major urban and industrial centers in the United States. The climate gradient across New England is one of the steepest in the country. Even though the region is small geographically, the region is influenced by both polar and tropical air masses.



London killer fog december 1952
London Killer Fog, December, 1952 Englanders

UK Met Office, 2009


Common pollutants that are of human respiratory health concern
Common pollutants that are of human respiratory health concern

Sulfur dioxide (SO2)

Nitric oxides (NOx)

Ozone (O3)

Carbon dioxide (CO2)

Particulate matter (PM)


Air pollutants could impact atopic disease at various levels
Air pollutants could impact atopic disease at various levels concern

Allergen

Sensitization

Allergic inflammation,

Bronchial hyperreactivity

Symptoms

(wheeze, cough, sneeze, etc.)

Pollutant

“Adjuvant” or “cause”

“Exacerbating factor”

Pollutant

“Trigger”

Pollutant



Age related association of pm and ozone with asthma hospitalizations
Age-related association of PM and ozone with asthma hospitalizations

Estimated relative risks of asthma hospitalization per IQR (interquartile range) increase in the average PM (12 µg/m3 ) and ozone (22 ppb) by age.

JACI 2010; 125: 367-73


Age related association of pm and ozone with asthma hospitalizations1
Age-related association of PM and ozone with asthma hospitalizations

Estimated relative risks of asthma hospitalization with increasing PM or ozone exposure.

JACI 2010; 125: 367-73


Effects of air pollution on asthma
Effects of air pollution on asthma hospitalizations

In patients with asthma, studies have shown that exposure to various pollutants has been associated with all of the following:

  • Increased ER visits and hospitalizations

  • Increased symptoms and medication use

  • Decreased pulmonary function

  • Increased bronchial hyper-responsiveness

  • Increased airway inflammation


Dep augments allergen specific ige in humans
DEP augments allergen-specific IgE in humans hospitalizations

Further…

Air pollution can interact with pollen grains, leading to an increased release of antigens thereby increasing allergenicity.

Air pollution can interact with paucimicronic allergen-carrying plant particles allowing them to be more easily inhaled to the peripheral airways.

IgE ( U/ml)

Effect of ragweed or ragweed plus DEP challenges on ragweed specific IgE in nasal washes.

(J Immunol. 1997; 158: 2406-13.)


Air pollution ozone or exercise as a cause of asthma
Air pollution (ozone) &/or exercise as a cause of asthma? hospitalizations

Effect of number of team sports played on the risk of

new asthma diagnosis in high and low ozone communities.

N = number of cases of asthma. RR = relative risk.

Lancet 2002; 359: 386-91.


Interaction of atopy and chlorinated pool exposure on rhinitis and asthma risk
Interaction of atopy and chlorinated pool exposure on rhinitis and asthma risk

Percent with hay fever

Percent with asthma

CPA (hours)

CPA (hours)

Prevalence of children with allergic rhinitis or asthma according to the CPA (chlorinated pool attendance) with atopic status.

Bernard et al. Pediatrics 2009; 124: 1110-8.

Bernard et al. Environ Health Perspect 2006; 114: 1567-73.


Air pollution as a cause of asthma
Air pollution as a cause of asthma? rhinitis and asthma risk

Increased risk of asthma in children living near roadways with high traffic volume. In primary school children the relative risk increased 1.8 per 30 meter increment.

(AJRCCM 2009; 164: 2177-80.)

Increased asthma in children living near petrochemical plants.

(JACI 2009;123: 632-8.)


Health benefits of o 3 reduction
Health benefits of O rhinitis and asthma risk3 reduction

Reduction in vehicle exhaust and O3 production during the 1996 Summer Olympic games in Atlanta, GA, resulted in a reduction of acute asthma care in children aged 1-16 years.

Percent decrease

Friedman et al. JAMA 2001; 285: 897-905.


Pollutant levels during the 1996 summer olympic games atlanta ga
Pollutant levels during the 1996 Summer Olympic Games, Atlanta, GA

Peak daily zone levels decreased 27.9%, from 81.3 ppb pre-Olympics to 58.6 ppb during the Olympic games. Peak weekday morning traffic counts dropped 22.5%.

Friedman et al. JAMA 2001; 285: 897-905.


Atmospheric co 2 concentration and temperature change
Atmospheric CO Atlanta, GA2 concentration and temperature change

Projected concentrations of CO2 during the 21st century are 2-4 times pre-industrial levels


Atmospheric co 2 concentration and temperature change 1860 2007
Atmospheric CO Atlanta, GA2 concentration and temperature change, 1860-2007

Changes in annual global mean surface temperatures and carbon dioxide concentrations since 1860 relative to 1961-1990 average values.


Health impacts of climate change
Health Impacts of Climate Change Atlanta, GA

Temperature-related illness and death

Extreme weather-related health effects

Air pollution-related health effects

Allergic disease

Water and food-borne disease

Vector-borne and rodent-borne diseases

Effects of food and water shortages

Mental, nutritional, infectious, and other health effects

Environmental refugees

Heat stress, cardiovascular failure

Injuries, fatalities

Asthma, cardiovascular disease

Respiratory allergies, asthma

Malaria, dengue, others

Cholera, crypotosporidosis, others

Malnutrition, diarrhea

Anxiety, PTSD, stress, depression

Forced migration, civil conflict

Climate change

Temperature

Heat waves

Extreme weather

Precipitation

Sea level rise



European heat wave 2003
European heat wave, 2003 increases

Confirmed excess mortality

Time line (France)

Mortality in 13 French cities during the August 2003 heat wave. Am J Public Health 2004; 94: 1518-20.

European mortality during the August 2003 heat wave. Public Health 2006; 120: 585-96.


Climate change and severe weather events 1972 2004
Climate change and severe weather events, 1972-2004 increases

Intensity of hurricanes (categories 1-5) 1970-2004, including number of storms by category (A) and proportion of storms in each category (B). Science 2005;309: 1844-6.


How much warming can we expect
How much warming can we expect? increases

2020-2029

2090-2099

Global warming 2.8ºC

IPCC 2007


Precipitation projections more rainfall for some less for others
Precipitation projections: more rainfall for some, less for others

December-February

June-August

IPCC


Effects of climate change on troposhperic ozone formation
Effects of climate change on troposhperic ozone formation others

Formation of ozone happens faster at high temperatures and with greater sunlight

VOC emissions increase at higher temperatures

Regional air mass patterns over time and space may change, altering stagnation and clearance events

The mixing height of the lower atmosphere may change, affecting the dilution of pollution emitted at the surface


Changing floristic hardiness zones
Changing floristic hardiness zones others

A major factor in determining hardiness is the average annual temperature. In the United States, recent shifts in global temperature have resulted in migration of these zones northward.


Climate change and allergic plants longer growing seasons and expanding range
Climate change and allergic plants: othersLonger growing seasons and expanding range

  • A meta-analysis of 1700 species (birds, butterflies, amphibians, herbs, shrubs, trees) showed:

  • Advancement of spring events by 2.3 days per decade

  • Range shift averaging 6.1 km per decade towards the poles

  • (Nature 2003; 421: 37-42.)

Start date of birch pollen season in Brussels; 1970-2006 (days after January 1).

Emberlin et al. 2002.


Effect of co 2 on ragweed pollen allergenicity
Effect of CO others2 on ragweed pollen allergenicity

With increased CO2 ragweed pollen was more allergenic. Ragweed allergen (Amb a 1) production increased as a function of CO2 concentration while

total pollen protein production was unchanged.

Singer et al. Funct Plant Bio 2005; 32: 667-70.


Urban heat island profile a model for climate change
Urban Heat-Island Profile: others A model for climate change ?


Effect of co 2 and temperature on ragweed physiology cities as harbingers of climate change
Effect of CO others2 and temperature on ragweed physiology: Cities as harbingers of climate change?

Biomass (A) and average catkin length (B) for ragweed as a function of [CO2] and air temperature during the pollen release period.

Ziska, et al. JACI 2003; 111: 290-5.


Effect of co 2 and temperature on ragweed physiology cities as harbingers of climate change1
Effect of CO others2 and temperature on ragweed physiology: Cities as harbingers of climate change?

Time course of ragweed pollen production in 4 for 2001 as a function of day of year (pollen grains per cubic meter of air).

Ziska, et al. JACI 2003; 111: 290-5.


Asthma on the rise
Asthma on the rise others

Explanations for the

increase in asthma and

allergy have included:

  • Air pollution

  • Dietary changes

  • Hygiene hypothesis

    • Childhood

      immunizations

    • Maternal smoking

    • Changing indoor

      environments

    • Use of antibiotics

    • Decreased exposure to endotoxin

  • ? Climate change

(Akinbami et al. 2009; NCHS, 2009)


Climate change and increased asthma
Climate change and increased asthma? others

“The links between aeroallergens and allergic disease such as asthma are well established. It is feasible that faster plant growth, earlier plant maturity, and longer growing season, plus earlier pollen season, increased season duration, and increases in both pollen quantity and allergenicity have already had an impact on asthma, reflected in the global rise in asthma prevalence and increased severity of episodes.”

Beggs and Bambrick. Environ Health Perspect 2005; 113: 915-9.


Climate change and global health ethical considerations
Climate change and global health: othersEthical considerations

Relative contribution to world-wide green house gas production.

Estimated mortality attributable to climate change.

Patz et al., 2007


Climate change and global health ethical considerations and vulnerability
Climate change and global health: othersEthical considerations and vulnerability

“The rich will find their world to be more expensive, inconvenient, uncomfortable, disrupted, and colorless – in general, more unpleasant and unpredictable. The poor will die.”

Kirk R. Smith, 2008

Professor: Environmental Health Sciences

University of California, Berkely


Summary pollution and climate change
Summary: Pollution and Climate Change others

  • Pollution is a significant health concern in this country and world wide

  • Pollution has adverse health consequences in patients with allergy and asthma

  • The contribution of pollution to asthma prevalence is uncertain

  • Climate change is real

  • Climate change is a significant global health and ethical issue

  • Climate change has potential for significant adverse health consequences in patients with allergy and asthma

  • To date, the effect of climate change on asthma is uncertain and impossible to predict


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