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We reviewed 47 documents published 1967-2019 that reported measurements of volatile organic compounds (VOCs) on commercial aircraft. We compared the measurements with the air quality standards and guidelines for aircraft cabins and in some cases buildings. Average levels of VOCs for which limits exist were lower than the permissible levels except for benzene with average concentration at 5.9±5.5 μg/m 3 . Toluene, benzene, ethylbenzene, formaldehyde, acetaldehyde, limonene, nonanal, hexanal, decanal, octanal, acetic acid, acetone, ethanol, butanal, acrolein, isoprene and menthol were the most frequently appearing compounds. The concentrations of SVOCs (Semi-Volatile Organic Compounds) and other contaminants did not exceed standards and guidelines in buildings except for the average NO2 concentration at 12 ppb. Although the focus was on VOCs, we also retrieved the data on other parameters characterizing cabin environment. Ozone concentration averaged 38±30 ppb below the upper limit recommended for aircraft. The outdoor air supply rate ranged from 1.7 to 39.5 L/s per person and averaged 6.0±0.8 L/s/p (median 5.8 L/s/p), higher than the minimum level recommended for commercial aircraft. Carbon dioxide concentration averaged 1,315±232 ppm, lower than what is permitted in aircraft and close to what is permitted in buildings. Measured temperatures averaged 23.5±0.8°C and were generally within the ranges recommended for avoiding thermal discomfort. Relative humidity averaged 16%±5%, lower than what is recommended in buildings.

This study explores the relationship of friendship characteristics, specifically perceived reciprocity and self-disclosure of menarcheal status, to physical similarity, pubertal status, and grade level. One hundred and twenty girls in fifth, sixth, and seventh grades were interviewed about their friendships. Each girl was asked to name her "best," "close," and ",other" friends, as well as whether the friendships were reciprocal, whether each friend would tell the subject when she began menstruating (or, if postmenarcheal, did tell), and vice-versa. Girls rated the similarity of each friends' physical development to their own physical development. A nurse rated the girls' physical development by the Tanner method.

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