Introduction:
Secondhand smoke (SHS) is a widespread health hazard. Smoke-free policies have commonly focused on locations that are more relevant for adults, neglecting SHS exposure at children areas. This study aimed to assess SHS exposure in children playgrounds, according to socioeconomic status (SES).

Methods:
We monitored airborne nicotine concentration and tobacco-related variables in 20 different playgrounds in 11 European countries (N=220 measurements). The fieldwork was carried out between March 2017 and April 2018. Playgrounds were selected according to the SES (half of them belonging to the most deprived neighborhoods and half of them to the least deprived neighborhoods). Vapor-phase nicotine levels were measured using active sampling. Furthermore, self-perceived wind, number of smokers, and butts inside playground and on playground surroundings were collected through a form. Nicotine concentrations were later dichotomized using the limit of detection (LOD) as a cut-off point (0.06 μg/m3).

Results:
Detectable levels of nicotine were found in 40.9% of the playgrounds. Median nicotine concentration was <0.06 μg/m3 (IQR:<0.06-0.127) and there were no statistically significant differences when considering neighborhood’s SES or the observer’s self-perceived wind. There were people smoking inside one out of five playgrounds. More than half of the sites showed presence of butts inside (56.8%) and just around (74.5%). Presence of butts inside playgrounds was higher in sites from a low SES (p<0.05).

Conclusions:
There is evidence of SHS exposure in playgrounds across Europe. These findings confirm the need of smoking bans in playgrounds in those countries that do not have legislation and a better enforcement in those countries that already have a smoking ban.