Electromagnetic Fields
Electromagnetic fields (EMFS) exist everywhere in our environment. These fields can be created by both natural sources, like thunderstorms, or can be man-made, like x-rays and high-frequency radio waves, with sources including radios, TVs and cell phones. EMFs are produced by electrical power generation, transmission and use, including all of our home’s wiring and all of our electrical systems, fixtures and appliances. EMFs at different frequencies interact with the body in different ways, depending on their frequency or corresponding wavelength. Since chemical reactions within our own bodies produce electrical currents, exposure to certain EMF fields can interfere with or cause a physical reaction, including changes in cell structure, tissues and hormones. How our bodies react to EMFs can vary due to our overall constitution and health. Research linking EMF exposure and a variety of health concerns is ongoing and, for the most part, inconclusive. There have been some fairly consistent patterns in EMF exposure and incidence of certain leukemia and other cancers. Of course, some individuals may be more sensitive to EMFs than others, and continued or high levels of exposure may have a higher impact on their health.
However, many, including the World Health Organization and the European Commission, agree that limiting our exposure is just common sense. This usually means distancing yourself from sources and limiting exposure times and frequency. To prevent any problems arising from continuous exposure to EMFS in the home, choose a building site that is not close to large overhead distribution transmission lines for electric utility services. Electric fields from power lines rapidly become weaker with distance and can be greatly reduced by the walls and roofs of buildings.
Your electrical design plan should allow for controlling circuits to limit your exposure, especially in sleeping areas, as our bodies are much more susceptible to these fields when relaxed. Avoid locating main living and sleeping areas in EMF hot spots,19 such as near electrical panel boxes, main service house connections, etc. Also, avoid running wiring to major electric appliances overhead or through walls of sleeping areas. Devices are available that can be programmed to shut off these circuit when you turn off the table lamp next to your bed. Since many clock radios, clocks on microwave ovens, electronic clocks, computer and television sleep modes mean that these appliances are actually in some state of “on” 24/7, having a switch to cut power to the circuits or a smart control that recognizes when they are not being used can significantly reduce our overall exposure.
Environmental Contaminants
Manufacturing processes related to building materials, from mining to production factories and transportation of products, often result in air, water and soil pollution. With oversight provided by the Environmental Protection Agency (EPA), the pollution generated from manufacturing processes is monitored and measured to legislated “acceptable” limits, although some might argue that any contamination is not acceptable. To reduce pollution, we must develop less polluting methods for extracting materials and manufacturing building materials. Products manufactured from recycled or waste materials, or from rapidly renewable resources have much lower impact on the environment than those sourced from mining and harvesting of virgin resources. Products made from locally sourced materials or manufactured locally have much lower embodied energies than those sourced and shipped long distances. It also generally uses less energy to ship raw materials some distance to a local factory than to ship finished goods over great distances. Bulk shipments of wood components or rail cars full of metal ore have a lower environmental impact than the number of shipments required for the volumes of finished manufacturer goods, especially when each container holds only one finished cabinet box or kitchen appliance.
- Sustainable Manufacturing Practices:
Many product manufacturers have improved their processes to produce less waste in manufacturing. Additionally, some manufacturers have voluntarily adopted and implemented more sustainable manufacturing practices, both as cost- saving measures and in order to be better citizens. The International Organization of Standardization (ISO) has a voluntary Environmental Management Standard program that supports manufacturers in setting and monitoring goals aimed at improving their environmental stewardship. ISO1400120 is the third-party designation for companies that participate in that program.
- Greenhouse Gases:
Air pollution in the form of ozone, particulate matter and greenhouse gases in our atmosphere can all contribute to climate change. Burning fossil fuels to generate electricity in order to power our homes, industries and automobiles, as well as the methane gases created from large cattle operations and landfills, have exponentially increased the amount of greenhouse gas released and trapped in the atmosphere. Building construction activities contribute to these issues. Strategies to reduce the carbon footprint related to our housing and lifestyle choices are discussed in depth in later article.
- Light Pollution:
Another type of pollution that is not commonly recognized is that produced by outdoor lighting in the form of light pollution, also known as light trespass. Many nocturnal creatures are dependent upon dark skies to hunt for food, find water sources or navigate their annual migration patterns. Light pollution interferes with their normal functions and can adversely affect their ability to move around, choose safe nesting places or avoid their predators. One example of this is reflected in a study that found baby sea turtles that naturally use the direction of star and moonlight reflected off the water surface to help them find the ocean when they emerge from their beach nests may turn the wrong way and migrate toward the brighter lights of buildings or streetlamps, often resulting in death.
Contributions to light pollution come from our outdoor porch lights that throw light up into the night sky, soffit floodlights that light up long distances in our yards, billboards, business signs, street lights and parking lot floodlight systems and numerous other sources that we no longer take notice of. Almost everyone has seen satellite images of our planet at night and the huge areas that are blasting light out into the cosmos. Of course, it takes electrical power to generate all of this light, again contributing to more greenhouse gases and climate change.
Few of us ever consider the impact that this 24/7 light has on our health or that of other inhabitants of the planet. Plant life is dependent on daily and seasonal natural light patterns to produce fruit, shed and grow leaves, grow roots and stems and go dormant. Light pollution affects these natural cycles and can result in permanent evolutionary changes to some species.
Therefore, it is important that we take steps to minimize light pollution and trespass wherever possible. If your home will be located where nighttime light pollution is unavoidable, it’s wise to take steps to ensure that your bedroom windows have the necessary treatments to create a truly dark sleep environment. For safety lighting, choose exterior light fixtures that are shielded from above, styles that have a solid top that prevents light from shining upward. Also, limit landscape lighting and select fixtures that throw light exactly where you need it, without lighting up unnecessary areas. Choose fixtures specifically for path or deck lighting and landscape fixtures that spot particular features in the landscape. Better yet, limit outdoor lighting to what is needed for safety and security. If you feel the need to use floodlights, make them motion activated and set sensitivity to respond only to larger predators (like a burglar), not small, nocturnal creatures.
- Noise and Other Pollution:
The hazardous effects of noise depend on its intensity, pitch, frequency and duration. Exposure to over eight hours of sound in excess of 85 decibels a day23 is potentially dangerous. In addition, noise can be harmful to animals and the environment. Noise can disturb normal functions of wildlife, including feeding and breeding.
Sources of noise pollution that affect the home include vehicular traffic and aircraft, commercial and industrial activities, HVAC system operations and common household appliances, like vacuum cleaners, exhaust vent fans and lawn equipment. Methods to control this include reducing exposure, wearing ear protection or using something to block the path of transmission. Site selection for our homes should include an analysis of exposure to noise-producing pollutants, like proximity to highway traffic or industrial manufacturing. Trees and shrubs can also disrupt sound waves from external sources, as does insulating the exterior walls and ceilings of our homes. We can also sound-insulate the interior walls of internal sources like media, laundry or bathrooms. There are new types of drywall that have very high sound transmission class (STC) ratings, which measure how well a building partition attenuates sound. In the case of a media room, sound-attenuating drywall, double layers of drywall and offset double stud walls, are all good ways to control interior sound sources. Internal sources of sound pollution should also be considered and dealt with during the design phase, such as locating the HVAC air handler in the attic or in an insulated closet. The same concern could be expressed for pollutants that affect our other senses, including smell, taste, vision and touch. We would not want a home located downwind of a landfill or close to a stockyard. We would also find it difficult to live on a landscape reclaimed from a toxic chemical dump, so best to think about these things when selecting your building site.
