Danger from Home 来自家中的危险



Most people are aware that outdoor air pollution can damage their health, but many do not know that indoor air pollution can also have significant health effects. Environmental Protection Agency studies indicate that indoor levels of pollutants may be 2～5 times, and occasionally more than 100 times, higher than outdoor levels. These levels of indoor air pollutants may be of particular concern because most people spend about 90％ of their time indoors.

There are many sources of indoor air pollution in any home. These include combustion sources such as oil, gas, coal, wood, and tobacco products; building materials and furnishings as diverse as deteriorated asbestos-containing insulation, wet or damp carpet, and cabinetry or furniture made of certain pressed wood products; products for household cleaning and maintenance, personal care, or hobbies; central heating and cooling systems and humidification devices; and outdoor sources such as radon, pesticides, and outdoor air pollution.

Immediate effects may show up after a single exposure or repeatedexposures. These include irritation of the eyes, nose, and throat, headaches, dizziness, and fatigue. Such immediate effects are usually short-term and treatable. Sometimes the treatment is simply eliminating the person's exposure to the source of the pollution, if it can be identified. Symptoms of some diseases, including asthma, hypersensitivity, pneumonitis, and fever, may also show up soon after exposure to some indoor air pollutants.

The likelihood of immediate reactions to indoor air pollutants depends on several factors. Age and pre existing medical conditions are two important influences. In other cases, whether a person reacts to a pollutant depends on individual sensitivity, which varies tremendously from person to person. Some people can become sensitized to biological pollutants after repeatedexposures, and it appears that some people can become sensitized to chemical pollutants as well.

Certain immediate effects are similar to those from colds or other viral diseases, so it is often difficult to determine if the symptoms are a result of exposure to indoor air pollution. For this reason, it is important to pay attention to the time and place the symptoms occur. If the symptoms fade or go away when a person is away from the home and return when the person returns, an effort should be made to identify indoor air sources that may be possible causes. Some effects may be made worse by an inadequate supply of outdoor air or from the heating, cooling, or humidity conditions prevalent in the home.

Other health effects may show up either years after exposure has occurred or only after long or repeated periods of exposure. These effects, which include some respiratory diseases, heart disease, and cancer, can be severely debilitating or fatal. It is prudent to try to improve the indoor air quality in your home even if symptoms are not noticeable.

While pollutants commonly found in indoor air are responsible for many harmful effects, there is considerable uncertainty about what concentrations or periods of exposure are necessary to produce specific health problems. People also react very differently to exposure to indoor air pollutants. Therefore, further research is needed to better understand the effects of indoor air pollution and to find efficient ways to protect our health.

　 大多数人都意识到了室外空气污染对健康有害，但是很多人却不清楚室内空气污染也会对健康产生严重的影响。环境保护机构的研究表明，较之室外空气污染，室内空气污染程度或许要高出2～5倍，有时甚至100多倍。由于多数人大约90％的时间都在室内度过，室内空气污染的这种程度应当引起人们的特别关注。

在家里有许多室内空气污染源，包括诸如油、煤气、煤、木头、烟草制品等燃烧时产生的气体；不同种类的建筑材料和装饰材料，如变质的含有石棉成分的绝缘材料、潮湿的地毯、用密度板制成的橱柜或者家具；用于家居清洁维护、个人护理和个人癖好的各种产品；中央冷暖空调系统和加湿设备；来自室外的污染源，如氡气、杀虫剂和室外空气污染。

接触过一次或反复接触这些污染源就会马上产生反应，包括眼睛、鼻子、嗓子感到刺痛，头疼，头昏，以及疲倦。这些即时反应通常只是短暂的，而且可以治愈。有时，简单的治疗方法就是，如果能够确认污染源，那么就设法进行阻断。接触了某些室内空气污染源后，也可能迅速出现某种疾病的症状，这类疾病包括哮喘、过敏、肺炎以及发烧。

对室内空气污染可能产生的即时反应取决于几个因素。年龄以及原已存在的体质状况是两个重要的因素。在其他情况下，一个人是否对污染物产生反应，取决于该人对此物质的敏感度。在这一点上人与人之间的差异极大。有些人多次接触生物污染物后会产生反应，而有些人则对化学污染物过敏。

有些即时反应与感冒或其他病毒感染疾病的症状相似，所以经常很难确定这些症状的罪魁祸首是不是室内空气污染。因此，关注症状发生的时间和地点是很重要的。如果一个人离开家时症状减轻或消失了，而一回到家症状又出现了，那么人们就应当确定可能引起症状的室内空气污染源。缺乏足够的室外空气供应，及家中普遍拥有的冷暖气和加湿设备可能会加重室内空气污染。

室内空气污染对健康的其他影响可能在接触污染源若干年之后开始显现，或者经过一段长时间的反复接触后才开始显现。这些影响包括某些呼吸道疾病、心脏病以及癌症，它们会严重损害健康，或产生致命的后果。所以，即使尚未觉察到什么症状，也要注意努力改善家中的空气质量。

室内空气中发现的污染源会对健康造成许多有害的影响，但是很难确定污染源的密度要有多大，或接触污染源的时间要有多长，才能引发某一特定的健康问题。此外，接触到室内空气污染源后的反应在人与人之间存在极大差异。因此，有必要对室内空气污染进行进一步研究，以便更好地了解室内空气污染的影响并找到保护我们健康的有效方法。
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