N95口罩的呼吸阻力还蛮大的，现在专家一般不建议给小孩，老人和有呼吸，心血管疾病的人带口罩。另，滤片的面积比口罩小，谨慎估计这个面具比口罩阻力大些。

很多品牌是不出小孩子口罩的，不贴合是一个原因，影响呼吸也挺重要的。
3M的Q&A里提醒3岁以下小孩带口罩可能引起窒息：
http://multimedia.3m.com/mws/mediawebserver?mwsId=66666UuZjcFSLXTtmxMcoxMyEVuQEcuZgVs6EVs6E666666--
Can children wear respirators?
3M disposable respirators are designed for adult faces and not for children. Very young children, or children with very small faces, may not be able to achieve a good fit. In addition, children may not be able to follow the fit instructions or to keep the respirator on their face during the entire time they are in a contaminated area. Children under three should not wear a respirator or mask as it may be a suffocation or choking risk. Contact your local health authority if you have questions about children’s health.

respro的网站上表示不建议11岁以下小孩带口罩：
http://respro.com/pg/faqs#faq15
Are children’s masks available?
Our concern in providing masks for children is that the size variation in children is so wide, that a ‘childs’ mask will not fit the range of sizes that children come in. A 3-year-old will not require the same mask sizes as a 7 -to 10-year-old. We do not recommend the use of face masks for children younger than 11 years, but to seek alternative ‘common sense’ precautions ie hood on push chairs, keep away from large congested or dense traffic environments; if you cannot, then place something in front of their faces more like a guard to prevent air/wind/ polluted air from direct contact.  Children’s breathing rates are considerably lower that that of a walking adult so they should not be in too much danger. Generally common sense practice where at all possible should be considered. If a child has a particular respiratory issue then medical advice should be considered first and foremost.

通过剪裁口罩使得适合小孩脸型是个好主意，不过其他风险就不好说了。自己权衡吧。
重污染天还是在家待着比较好
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FROM 106.120.83.*