Air Pollution: An Unseen Allergen, A Health Hazard

Air pollution is a major environmental risk to human health, with 9 out of 10 people on Earth breathing highly polluted air. It is therefore unsurprising that air pollution can cause allergies, with symptoms including itchiness, a scratchy throat, a runny nose, sneezing, and watery eyes. Allergies are an exaggerated response by the immune system to exposure to certain foreign substances, and air pollution is one of the most common causes. Allergies to air pollution can be managed by reducing exposure to air pollutants, and in some cases, treated with medication.

Pollution allergy symptoms

Pollution allergies are a real concern for people who suffer from allergic rhinitis, a common allergy that affects up to 40% of people worldwide. The condition occurs when a person's immune system reacts to allergens in the air, such as pollen, dust mites, or mould, causing inflammation of the inside of the nose.

Air pollution, caused by industrial development and an increasing number of vehicles on the road, is making it harder for people to escape these allergens. A recent WHO study found that 9 out of 10 people on Earth breathe highly polluted air.

Symptoms of a Pollution Allergy

People who suffer from a pollution allergy can experience:

• Itchiness
• A scratchy throat
• A runny nose
• Sneezing
• Watery eyes

For those who suffer from other airborne allergies, especially pollen, these symptoms may intensify and might require medical assistance.

Other Health Effects of Air Pollution

Air pollution has been linked to a range of serious health issues, including:

• Allergic respiratory disease
• Asthma
• Chronic obstructive pulmonary disease
• Lung cancer
• Heart disease
• Strokes

Preventing and Treating Pollution Allergies

The best way to manage a pollution allergy is to limit exposure to air pollutants. This can include wearing a disposable face mask, especially when travelling in heavy traffic, and keeping windows closed to prevent pollutants from entering a room.

If allergies are triggered, non-sedative antihistamines or nasal sprays can be used to treat symptoms, but a doctor should be consulted for the right prescription.

There is currently no cure for pollution allergies.

Pollution allergy diagnosis

If you suspect that you have an environmental allergy, you should see an allergist. They will ask you about your symptoms, medical history, and family history. They will then use this information, along with the results from allergy testing, to identify specific allergens that may be causing your symptoms.

Allergy Testing

There are several types of allergy tests that your doctor may choose from, depending on your symptoms and suspected causes.

Skin-Prick or Scratch Test

Your healthcare provider will use a thin needle containing an allergen to prick your skin. They may also put droplets of allergens on your skin and then scratch your skin so the allergens can enter. The test could be done on your forearm or back. If you are allergic, a rash or raised spots will appear within 15 minutes.

Intradermal Skin Test

If the skin-prick test does not provide enough information, your doctor may inject a small amount of an allergen into the outer layer of your skin. They will be looking for a rash or other reaction.

Patch Test

This test is used to check for contact dermatitis, which is a reaction that occurs when your skin comes into contact with an allergen. Your healthcare provider will put drops of an allergen on the surface of your skin and cover the spot with a bandage. The allergen may also be on the bandage itself. You will leave the bandage in place for at least two days before returning to your doctor, who will then check for a reaction.

Blood Test

Your healthcare provider will draw a blood sample and send it to a lab, where allergens will be added to your blood and then tested for levels of IgE antibodies. This test has a higher rate of false positives.

Oral Challenge Test

Typically, an allergy specialist will perform this test. You will swallow a small amount of a suspected allergen while a healthcare provider closely watches you in case you have an allergic reaction. If you do, you will be given an epinephrine shot to stop the reaction.

Preparing for an Allergy Test

To prepare for an allergy test, you will need to stop taking your allergy medication 3 to 7 days in advance. These drugs can interfere with the test.

Pollution allergy treatment

Yes, it is possible to be allergic to pollution. Here are some ways to treat pollution allergies:

Avoidance

The best way to treat pollution allergies is to avoid exposure to pollution. Here are some ways to do that:

• Wear a mask — A certified N95 mask can protect you from polluted particles in the air.
• Check the Air Quality Index (AQI) — Before leaving home, check the AQI. If the level is high, stay indoors and avoid outdoor activities.
• Use an air purifier with a HEPA filter — Even when doors and windows are shut, polluted particles can still enter your home. A HEPA filter can block fine particles better than a regular filter.
• Campaign against burning — Reduce everyday activities that produce smoke, such as driving and using incense.

Medication

If you are experiencing allergy symptoms, there are several over-the-counter and prescription medications that can help:

• Antihistamines — These can be taken to treat allergy symptoms. Non-drowsy antihistamines are also available.
• Nasal sprays — These can be used to ease allergic symptoms and decongest blocked nasal passages.
• Steroid nasal spray — For severe nasal allergies or sinusitis, a steroid nasal spray can be used to reduce swelling in the sinus and nasal passages.
• Controller medication — For asthma, daily use of controller medication can prevent deterioration of lung function and acute respiratory failure.

Immunotherapy

Immunotherapy helps to reduce the body's allergic reaction to allergens. It usually takes 3–5 years, depending on the patient's responsiveness and the treatment's side effects. Immunotherapy includes subcutaneous injections and sublingual medication.

Surgery

In severe cases of sinusitis or misalignment of the nasal passage, surgery may be required. However, this should only be determined and prescribed by a medical specialist.

Pollution allergy prevention

Overview

Allergies are one of the most common chronic diseases. They occur when the body's immune system identifies a substance as harmful and overreacts to it. The substances that cause these reactions are called allergens.

Air pollution is one of the major factors associated with the development of chronic allergic respiratory diseases. A recent WHO study found that 9 out of 10 people on Earth breathe highly polluted air.

Preventing Exposure to Indoor Airborne Allergens

The Environmental Protection Agency recommends three ways to improve indoor air quality:

• Control your contact with indoor airborne allergens
• Ventilate indoor areas well
• Use air cleaners to clean indoor air

Preventing Exposure to Outdoor Airborne Allergens

• Wear a disposable face mask, especially when travelling in heavy traffic
• Keep windows closed to prevent pollutants from getting inside and use an AC to clear the air inside your room
• Avoid smoky rooms
• If you smoke, consider giving up to help those suffering from allergies
• Avoid using strong perfumes and ask your friends/family to do the same, especially when those suffering from allergies are likely to be hypersensitive

Preventing Exposure to Pet Allergens

• Keep pets out of your bedroom
• Close the doors to bedrooms when you are not home to keep pets out
• Cover vents with dense material like cheesecloth
• Wash and change your animal’s favourite furniture and toys often
• Bathe your pets regularly to reduce the amount of dander
• If your pet goes outside, regular baths can also reduce the risk of them tracking in allergens like pollen

Preventing Exposure to Mould Allergens

• Reduce moisture around the bathroom, kitchen and other areas where there is a lot of water
• Don’t run your showers for a long time before bathing
• Use dehumidifiers to reduce both mould and dust mites
• Use humidity monitors
• Limit yourself to a few house plants
• Fix all leaks and other causes of damp areas
• If you see mould on a surface, clean it immediately. Wear a mask and clean the surface each week to keep it from returning

Preventing Exposure to Cockroach Allergens

• Do not leave food or garbage uncovered
• Use poison baits, boric acid and traps instead of chemicals, as these may irritate your sinuses and asthma

Pollution allergy and asthma

Air pollution is a mixture of gases, chemicals, and small particles in the air that can be harmful to human health and the environment. It is a major risk factor for developing asthma and other lung diseases, and it can also worsen existing asthma symptoms, leading to increased hospital visits and even early death.

Outdoor Air Pollution

Outdoor air pollution is caused by both natural sources, such as volcanoes and wildfires, and human activities, such as industrial processes and vehicle emissions. The main gaseous pollutants include nitrogen dioxide (NO2), sulfur dioxide (SO2), ozone (O3), carbon monoxide (CO), and carbon dioxide (CO2), as well as heavy metals and volatile organic compounds (VOCs).

Ozone is a powerful oxidant that can cause persistent structural damage to the airways and lungs. It is often a component of smog and is more common in cities with high traffic and the use of fossil fuels. Nitrogen dioxide, primarily from vehicle emissions and power plants, can cause asthma and worsen lung diseases. Sulfur dioxide, released from burning fossil fuels and industrial processes, can harm the lungs and lead to health problems. Carbon monoxide, formed from incomplete combustion, is dangerous when it builds up indoors.

Particulate matter (PM) refers to small airborne particles found in haze, smoke, soot, and dust. The smallest particles, known as PM2.5, are the most dangerous as they can penetrate deep into the lungs and even enter the bloodstream. These particles can irritate the airways, trigger asthma attacks, and lead to respiratory diseases.

Indoor Air Pollution

Tobacco smoke, including second-hand smoke, is a significant indoor air pollutant. It contains over 7000 chemicals and is a major risk factor for developing respiratory diseases, including asthma. Other indoor pollutants include heating sources, such as wood-burning stoves and unflued gas heaters, which can emit harmful gases and particles. Molds and fungi are also indoor pollutants that can trigger asthma and respiratory issues.

Impact on Asthma

Air pollution can trigger asthma symptoms, including wheezing, coughing, chest tightness, and difficulty breathing. It can also lead to exacerbations, requiring emergency treatment and hospitalization. Long-term exposure to air pollution can cause a decline in lung function and increase the risk of developing asthma, especially in children.

People with existing asthma are particularly vulnerable to the effects of air pollution. Exposure to pollutants can irritate the airways, trigger asthma attacks, and lead to a need for increased medication. Additionally, indoor air pollution from sources such as tobacco smoke, cooking with polluting fuels, and mold can negatively impact asthma control and lung function.

Preventive Measures

To reduce the impact of air pollution on asthma, it is essential to minimize exposure. This includes personal strategies such as wearing masks, avoiding areas with high traffic, and staying indoors during periods of poor air quality. Community-level interventions, such as urban planning with more green spaces and walking paths, can also help reduce exposure.

For individuals with asthma, following asthma management guidelines and using controller medications as recommended are crucial. Dietary supplements and a healthy diet, such as the Mediterranean diet, may also help reduce the impact of air pollution.

On a larger scale, governments and public health authorities must implement measures to reduce air pollution, such as monitoring air quality, enforcing smoke-free indoor environments, and promoting the use of cleaner fuels and technologies.

Frequently asked questions