Radon as Indoor Air Pollutant: Should You Be Concerned?

When the topic of indoor air pollution is mentioned, there are a few main sources that most likely come to mind.石棉, carbon monoxide, andformaldehydeare a few major concerns that the average person would likely associate with室内空气质量. However, in recent years there has been a growing concern with a less prevalently known indoor air pollutant: radon gas.

什么是氡气？

化学说话，氡是无色，无味的，无味的放射性惰性气体。该气体由稀镍的腐烂产生，其可以在许多常见的矿物质中发现，例如铀和/或磷酸盐矿石。几乎所有岩石都含有至少一些浓度的铀，通常约为1 - 3 ppm（Michaela Kreuzer，2010）。氡气，当从岩石和土壤中释放时，经历放射性衰减以产生一系列后代。

These progeny, also referred to as daughters, are capable of emitting different levels of radiation (i.e.: alpha, beta and gamma). The alpha radiation of not of much concern, however beta and gamma radiation is capable of penetrating the skin and has been shown to pose serious health risks at certain exposure levels (Michaela Kreuzer, 2010). These decay products are very electromagnetic, meaning that once in the air they are likely to attach to particulate matter and become inhaled into the respiratory system.

How are we exposed to radon gas?

Radon gas is present in both air and water. When present in outdoor air, radon gas is typically so dilute that it does not pose any serious concern. It is when we talk about indoor or household air that radon becomes troublesome.

The main source of radon gas exposure by air is through the decay of uraniferous rocks and soils present under and/or adjacent to the foundation of a home or building. Many homes built on uranium containing soil will have cracks or fractures in the foundation, which allows for the pressure-driven seepage flow of radon gas from the cool air of the soil to the warmer air present within the building as it decays. This risk is higher for homes or buildings with poorly-sealed foundations, older homes, and homes built on a soil with high permeability. Even if the uranium content in the soil surrounding this category of home is moderate, the radon gas can still concentrate within the indoor air and cause the levels to be very high. Of course it goes without saying that homes built on soils containing high uranium concentrations are also at high risk. These soils can include light-colored volcanic rocks, granites, dark shales, sedimentary rocks that contain phosphate, and metamorphic rocks derived from these rocks. These rocks and their soils may contain as much as 100 ppm uranium (Michaela Kreuzer, 2010). It should be noted that there are many cases of homes built on uranium rich soil with low levels of radon gas in their indoor air, whereas there are many cases of homes built on uranium poor soil with high levels of radon in their indoor air.

很明显，土壤和周围土壤之间的空气压力差异，家庭基础质量和土壤的铀浓度是在确定氡气曝光的风险水平时发挥作用的所有因素。特别的家（加拿大政府，2016年）。此外，氡气也可以发现自己通过水系统进入房屋。世界上大部分地表水含有很少的氡，因为它暴露在大气中，使其逸出到空气中并稀释自身以安全透气的浓度。许多市政水处理厂允许他们的水进行曝气处理，这还促进了氡气从水源释放和稀释。因此，大多数依赖地表水的家庭对通过水系统进入的氡（Michaela Kreuzer，2010）没有担忧。地下水在氡气曝光方面构成了更多的关注。在许多家庭和社区中，地下水用作初级水源。许多使用主要是地下水的私人井和较小的处理设施，使用短途时间短，不允许发生氡的曝气或衰减。这意味着地下水中存在的任何氡气将能够通过淋浴，洗衣机，水龙头，洗碗机或任何其他水的供应者逸出到家庭或建筑物的室内空气中。 These circumstances typically occur to homes residing on uranium rich soils and using groundwater as their primary water source (Government of Canada, 2016). Contaminated groundwater can contribute to radon gas exposure by means of ingestion and inhalation, though inhalation is far more prevalent in terms of path of entry.

为什么担心氡气？

Now knowing what radon gas is and how humans can be exposed to it, it is also important to consider why one should be wary about radon gas exposure. It was only during the late 1960’s to early 1970’s that the negative health effects of radon gas and its decay products were proven. The first major concern with radon gas exposure is lung cancer, which was initially brought to light during the 1960’s through the effect it was having on miners. It wasn’t until 1988, after a prolonged trend consistently demonstrating the increase in lung cancer corresponding to an increase to radon exposure was observed, that radon gas was declared a classified human carcinogen by the International Agency for Research on Cancer (IARC) (Michaela Kreuzer, 2010). Since then, there has been a significant increase in the amount of research performed surrounding the effects of radon gas as a human carcinogen.

在同情吸烟,氡气暴露been proven to be the second leading cause of lung cancer in humans. In Canada alone, 16% of total lung cancer deaths can be attributed to radon gas exposure (Government of Canada, 2012). Disharmonious to cigarette smoking, exposure to radon gas will not produce any noticeable symptomatic effects such as coughing or headaches.

The chances of radon gas exposure leading to lung cancer is dependent on the concentration of radon in the air one breathes and the length of time exposed. The time between exposure and the onset of lung cancer is typically many years. Radon gas has the ability to cause lung cancer due to its radioactive traits. The decay products of radon are capable of electromagnetically attaching themselves to particulates present in the air. Once inhaled, these decay products breakdown further and further within the body, producing alpha, beta and gamma emitting particles. It is the deposition of the decay products in the airway that allows for the irradiation of lung tissue cells by alpha particles. These alpha particles are capable of letting out small bursts of energy that are subsequently absorbed by the sensitive lung tissue, damaging or killing the surrounding tissue cells (UNSCEAR, 2008). Damaged lung cells have the potential to reproduce as cancerous cells as they replicate.

除了肺癌是主要的健康问题，还在执行研究以观察氡气曝光和白血病之间可能存在的任何相关性，以及其他癌症。到目前为止，只能得出结论，有足够的证据证明氡原因
lung cancer, even at concentrations typically found in indoor air (Government of Canada, 2012).

What can we do about Radon gas?

The only way to tell if a home to susceptible to elevated levels of radon gas is to have it tested. Because the levels of radon gas can vary based on recipitation, barometric pressure, and other influences; indoor radon gas levels can vary from day-to-day. For this reason, it is recommended to have a long term radon gas test performed by a certified testing company, typically for a minimum of three months(Government of Canada, 2016). If the radon levels in the home are found to be higher than the guideline concentration of 200 Bq/m3 ,there are a number of actions one can take to reduce the radon gas levels (Government of Canada, 2016).

The first action one can take isventilating the basement亚地板虽然安装了一个小型泵，这将从基础下方将氡绘制，并使它在外部空气中稀释，然后才能在家中集中精力。还可以通过热回收呼吸机（HRV）机械地增加通风。除此之外，密封基础墙壁，排水管和水系统入口/网点中存在的所有裂缝和裂缝将停止氡气渗入家中并减少空中浓度（戈达，1989）。

如何减少家中的氡水平

When the radon levels in your home exceed Canada’s guidelines, stating 200 becquerels/m3, it’s time to seek professional help in reducing radon levels to an acceptable measure. The higher the radon levels, the more urgent it is to remediate.

According to a National Research Council report for the Environmental Protection Agency (EPA), eliminating radon gas entirely from your indoor living environment is not possible. The report explained that a third of lung cancer cases caused by radon exposure could be prevented if homes met the Canadian guideline.

以下是帮助您减少家中氡水平的提示，以便他们处于安全可接受的水平：

• Increase the ventilation in your hometo allow the air to properly circulate. You might want to try increasing mechanical ventilation through a heat recovery system (HRV) to permit air exchange.
• Seal all cracks, holes, or openings(水、污水、电力等)的基金会n walls and floors (basement). Also, seal the joints between walls and floors and the gaps around pipes and drains (i.e. all the vents through which radon gas can possibly enter your house).
• Cover sump pumps and drains(keeping in mind, of course, that this does not prevent their functioning).
• Replace your basement floors(particularly earth floors) with concrete floors. This reduces the risk of radon gas entering your home.
• 使用最常见的减少氡水平的方法s - 一个粉丝和管道，从室内绘制氡并驱逐出来。该方法通常被称为子平板减压，并在进入您的家之前排出氡。
• Install specially-designed traps在地板排水管中以防止氡进入地下室。
• 地下室楼层可通风by installing a small pump. This will draw the radon gas below the concrete slab to the outside.
• 安装有源土压抑（ASD）系统, which will reduce the concentration of radon in the soil next to your home’s foundation.
• Paint your basement floors and walls.Don’t forget to use a sealant on top of the paint and to add polyethylene sheets to the basement walls.
• In extreme cases, such as when unacceptable levels of uranium are found in the soil around your house, remove the soil and replace it with clean fill.
• New homes with radon-resistant features should be built following radon-resistant construction techniques, which are simple and inexpensive.

Your home is your greatest investment. Take precautions while the home is being built and you’ll minimize the risk of radon exposure.

氡减少新房子的提示

There are a number of ways you can reduce radon in new homes:

• Use highly resistant concrete
• Add plasticizer to the concrete
• Install a polyethylene membrane under the concrete
• 安装一个平衡通风system
• Install a pipe that runs across the concrete slab in case you need to install a depressurization system in the future.
• Make sure that your new home is being built following the 2010 new national building codes.

所有这些预防措施都应在施工时拍摄，而不是之后。

Finding a certified, trained and experienced professional in your city is the best and most reliable way to ensure that your home is not at risk of dangerous radon levels. Because each home is unique in its structure, its location, and therefore, its vulnerability to radon gas entry, testing and reduction should be done by trained and experienced professionals, who can also provide useful advice for the occupants’ future safety.

官网入口模具破坏者，加拿大领先的氡测试公司和室内空气质量(IAQ) testing是在渥太华，多伦多，蒙特利尔和许多其他城市。Call ustoday for a quick and effective solution to your radon problem.