Wildfires in BC

With climate change on the rise, wildfires in British Columbia (BC) are a growing and serious threat. In the last seven years, BC experienced four of the most severe wildfire seasons in history in 2017, 2018, 2021, and 2023.¹  Weather plays a huge role in wildfire activity with higher temperatures and lower humidity increasing fire activity.² As a result, the increasing severity of wildfire seasons in both length and activity is a consequence of the drier and hotter summers in BC caused by climate change, which may only get worse. Wildfire activity refers to the occurrence and condition of a fire³ while wildfire season length is defined by the time between the first and last fire of the year.⁴

The 2023 season was the most destructive, in BC alone, more than 2.84 million hectares of forest burned, tens of thousands of people forced to evacuate, and hundreds of homes lost or damaged.⁵ Homes and forests were not the only aspects impacted by the threat of wildfires, as smoke released can be hazardous to human health as well. 

Wildfire Smoke and the Impact on Health

Wildfire smoke is a form of air pollution that causes long-lasting health effects. Its composition of gases, particles, and water vapour may cause a threat, however, the main risk from wildfire smoke are fine particles known as fine particulate matter (PM_2.5). ⁶ Fine particulate matter are small particles 2.5 micrometers in diameter and consist of microscopic soot sticking together.⁶ They are extremely small, for reference, the width of a human hair is around 50 micrometers.  Their size allows them to enter the lungs during inhalation with some particles potentially entering the bloodstream.⁶ After exposure to wildfire smoke, different symptoms can be experienced based on the severity of the exposure. 

Possible Symptoms from Wildfire Exposure7

• Sore throat • Eye irritation • Runny nose • Cough • Phlegm production • Wheezy breathing • Headaches • Shortness of breath • Severe cough • Dizziness • Chest pain • Heart palpitations

In addition, wildfire smoke can increase the risk of respiratory morbidity which includes asthma, bronchitis, chronic obstructive pulmonary disease, and pneumonia.⁸ 

Certain individuals are more susceptible to the negative health effects of wildfire smoke than others such as those who are elderly, children, have pre-existing chronic conditions such as asthma, chronic obstructive pulmonary disease (COPD), or are pregnant.⁴

Effects of Wildfire Exposure During Pregnancy

There are so many different biological changes occurring during pregnancy which can lead to increased sensitivity of exposures to chemicals, radiation, or other hazards.⁹ Due to an increased chance of health risks when exposed to environmental chemicals, limiting this can help ensure healthy development of the baby.

There are many risks to the unborn child when pregnant individuals are exposed to wildfire smoke.

Though there is evidence supporting the risk wildfire smoke poses on unborn babies, there is minimal evidence on how exactly prenatal wildfire exposure influences a child’s health and development. We launched our research, the BC Wildfire Study, based on the Developmental Origins of Health and Disease hypothesis that early life exposures can impact health long-term and the limited research conducted in this topic. The BC Wildfire Study strives to better understand the risks of wildfire exposure during pregnancy in the next generation. Specifically, our research aims to study the impacts of prenatal wildfire exposure on children’s health and development.

BC Wildfire Study Data Collection

For the BC Wildfire Study, scientists will analyze newborn dried blood spots, cheek swabs, survey responses, and data from government databases to understand the relationship between prenatal wildfire exposure and children’s respiratory health and development. 

In BC and Yukon, newborn dried blood spots are collected at birth for all newborns to test for rare or serious disorders through the Newborn Screening Program.  Usually, 4 spots are collected and 1-2 are used for testing while the extra blood spots are kept for up to ten years in case of future use. The BC Wildfire Study has received approval from BC Children’s Hospital and the University of British Columbia’s board of ethics to use these samples for our research.  

When blood spots are used for health research, the samples are assigned a study number to anonymize them so that any identifying information such as name, personal health number, or date of birth are removed to protect each individual’s privacy.

Two main ways through which wildfire exposure may affect health outcomes :

DNA Methylation	Certain environmental factors can change where a small chemical group (methyl) is added to DNA. This process can regulate our genes as different amounts of methyl groups added to DNA can cause various amounts of a gene to be expressed. 11
Inflammation	The body’s response to illness, injury, or anything that may not belong in the body. Inflammation in the body can be identified by measuring different molecules which are present during an inflammatory response12

These are two biological pathways through which experts believe the environment may affect our health and bodies. Our scientists will use these two methods to explore a relationship between prenatal wildfire exposure and children’s respiratory health and development using children’s newborn dried blood spots and cheek swabs. 

Why Does this Research Matter?

As no studies have been completed to understand the risks of wildfire exposure during pregnancy on children’s health and development, our research can better inform the health and well-being of the next generation of children. 

The Developmental Origins of Health and Disease hypothesis ¹³ states that early life exposures affect long-term health. This hypothesis contributes to why researching prenatal effects, which the BC Wildfire Study does, is crucial.

Our research can also educate people, especially those living in high-risk wildfire areas, on the effects of wildfire smoke exposure, allowing them to take the correct precautions. 

Glossary