Large particles are responsible for elevated bacterial marker levels in school air upon occupation
Large particles are responsible for elevated bacterial marker levels in school air upon occupation
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DOI：
10.1039/b418038k
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发表时间：
2005-01-01
影响因子：
--
通讯作者：
Larsson, L
中科院分区：
文献类型：
--
作者：
Fox, A;Harley, W;Larsson, L
细菌多糖(PG)中含有胞壁酸(Mur)，而革兰氏阴性细菌脂多糖(LPS)中含有3-羟基脂肪酸(3-OFAs)。因此，Mur和3-OHFA可作为评估室内空气中细菌水平的标志物。一所学校的初步调查表明，有人住的房间里的粉尘、PG和内毒素(pmolm(-3))水平都比没有人住的同一房间里高得多。在每种情况下，粉尘的Mur含量都增加了，羟基脂肪酸分布也发生了类似的变化，这表明细菌种群发生了变化。在这里，调查结果与另外两所学校的结果进行了比较。根据颗粒大小对所有3所学校的气溶胶进行了首次跟踪监测。在有人和无人的教室中，颗粒大小分布有很大的不同。在个别教室内，空气中直径为0.8微米的颗粒物浓度与二氧化碳浓度呈正相关。这表明，较大颗粒水平的增加是占领期间细菌标志物上升的原因。儿童可培养和不可培养细菌或细菌聚集体的释放(例如从剥落的皮肤)可能解释了这种现象。
Muramic acid (Mur) is found in bacterial peptidoglycan ( PG) whereas 3-hydroxy fatty acids (3-OH FAs) are found in Gram-negative bacterial lipopolysaccharide (LPS). Thus Mur and 3-OH FAs serve as markers to assess bacterial levels in indoor air. An initial survey, in a school, demonstrated that the levels of dust, PG and LPS (pmol m(-3)) were each much higher in occupied rooms than in the same rooms when unoccupied. In each instance, the Mur content of dust was increased and the hydroxy fatty acid distribution changed similarly suggesting an alteration in the bacterial population. Here, findings are compared with results from two additional schools. Follow-up aerosol monitoring by particle size was also performed for the first time for all 3 schools. The particle size distribution was shown to be quite different in occupied versus unoccupied schoolrooms. Within individual classrooms, concentrations of airborne particles >= 0.8 mu m in diameter, and CO2 were correlated. This suggests that the increased levels of larger particles are responsible for elevation of bacterial markers during occupation. Release of culturable and non-culturable bacteria or bacterial aggregates from children (e.g. from flaking skin) might explain this phenomenon.