Environment International 149 (2021) 105775 Contents lists available at ScienceDirect Environment International journal homepage: www.elsevier.com/locate/envint Secondhand smoke exposure in outdoor children’s playgrounds in 11 European countries Elisabet Henderson a, b, c, Xavier Continente a, c, d, Esteve Fernández e, f, g, h, Olena Tigova e, f, g, h, Nuria Cortés-Francisco a, Silvano Gallus i, Alessandra Lugo i, Sean Semple j, Rachel O’Donnell j, Luke Clancy k, Sheila Keogan k, Ario Ruprecht l, Alessandro Borgini l, Anna Tzortzi m, Vergina K Vyzikidou m, Giuseppe Gorini n, Angel López-Nicolás o, Joan B Soriano h, p, Gergana Geshanova q, Joseph Osman r, Ute Mons s, Krzysztof Przewozniak t, u, José Precioso v, Ramona Brad w, Maria J. López a, b, c, d, *, the TackSHS project investigators a Agència de Salut Pública de Barcelona, Barcelona, Spain b Departament de Ciències Experimentals i de la Salut (DCEXS), Universitat Pompeu Fabra, Barcelona, Spain c Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid, Spain d Sant Pau Institute of Biomedical Research (IIB Sant Pau), Barcelona, Spain e Tobacco Control Unit, Institut Català d’Oncologia (ICO), Barcelona, Spain f Tobacco Control Research Group, Institut d’Investigació Biomèdica de Bellvitge (IDIBELL), Barcelona, Spain g School of Medicine and Health Sciences, Universitat de Barcelona, Barcelona, Spain h Consortium for Biomedical Research in Respiratory Diseases (CIBERES), Madrid, Spain i Department of Environmental Health Sciences, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy j Institute for Social Marketing and Health, University of Stirling, Stirling, United Kingdom k TobaccoFree Research Institute Ireland, Dublin, Ireland l Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy m George D. Behrakis Research Lab-Hellenic Cancer Society, Athens, Greece n Istituto per lo Studio, la Prevenzione e la Rete Oncologica, Florence, Italy o Universidad Politécnica de Cartagena, Cartagena, Spain p Hospital Universitario La Princesa, Madrid, Spain q Smoke-free Life Coalition, Sofia, Bulgaria r OFT Conseil, Office Français de santé et bien-être au Travail, Paris, France s Cancer Prevention Unit & WHO Collaborating Centre for Tobacco Control, German Cancer Research Center (DKFZ), Heidelberg, Germany t The Maria Sklodowska-Curie Institute – Oncology Center, Warsaw, Poland u The Foundation Smart Health – Health in 3D, Warsaw, Poland v Instituto de Educação, Universidade do Minho, Braga, Portugal w Healthy Romania Generation 2035 Association, Bucharest, Romania A R T I C L E I N F O A B S T R A C T Handling Editor: Xavier Querol Introduction: Tobacco presence in outdoor children’s playgrounds is concerning not only because it leads to secondhand smoke (SHS) exposure, but also cigarette butt pollution and tobacco normalization. Keywords: Objectives: This study aimed to assess SHS exposure in children’s playgrounds, according to area-level socio­ Tobacco smoke pollution economic status (SES), smoke-free regulations, national smoking prevalence, and SHS exposure prevalence in Child playgrounds (2017–2018). Playground Methods: We monitored vapor-phase nicotine concentration and tobacco-related variables in 20 different play­ Socioeconomic status Smoke-free regulations grounds in 11 European countries (n = 220 measurements) from March 2017 to April 2018. Playgrounds were selected according to area-level SES. Data on the number of people smoking, and cigarette butts inside the playground and on playground surroundings (<1 m away) were recorded. Playground smoking bans, the To­ bacco Control Scale (TCS) score, national smoking prevalence and SHS exposure prevalence in playgrounds were Abbreviations: SHS, Secondhand smoke; SES, Socioeconomic status; TCS, Tobacco Control Scale; LOQ, Limit of Quantification; IQR, Interquartile Range. * Corresponding author at: Servei d’Avaluació i Mètodes d’Intervenció (SAMI), Agència de Salut Pública de Barcelona (ASPB), Pl. Lesseps, 1, 08023 Barcelona, Spain. E-mail address: mjlopez@aspb.cat (M.J. López). https://doi.org/10.1016/j.envint.2020.105775 Received 13 February 2020; Received in revised form 27 April 2020; Accepted 28 April 2020 Available online 20 November 2020 0160-4120/© 2020 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). E. Henderson et al. Environment International 149 (2021) 105775 used to group countries. To determine nicotine presence, we dichotomized concentrations using the limit of quantification as a cut-off point (0.06 μg/m3). Nicotine median concentrations were compared using non- parametric tests, and nicotine presence and tobacco-related observational variables using the Chi-squared test. Results: Airborne nicotine presence was found in 40.6% of the playgrounds. Median nicotine concentration was <0.06 μg/m3 (Interquartile range: <0.06–0.125) and higher median concentrations were found in more deprived neighborhoods, non-regulated playgrounds, in countries with lower overall TCS scores, higher national smoking prevalence and higher SHS exposure prevalence in playgrounds. Overall, people were smoking in 19.6% of the playgrounds. More than half of playgrounds had cigarette butts visible inside (56.6%) and in the immediate vicinity (74.4%). Presence of butts inside playgrounds was higher in sites from a low area-level SES, in countries with low TCS scores, and greater smoking prevalence and SHS exposure prevalence (p<0.05). Conclusions: There is evidence of SHS exposure in children’s playgrounds across Europe. These findings confirm the need for smoking bans in playgrounds and better enforcement in those countries with smoking bans in playgrounds. 1. Introduction non-biodegradable waste left within their reach. These tobacco leftovers contain toxins and carcinogenic substances, posing a potential hazard Secondhand smoke (SHS) is a widespread health hazard for which for children, who might play with or even swallow cigarette butts there is no safe level of exposure. The harmful effects derived from long- (Moriwaki et al., 2009; Novotny et al., 2011). term exposure to SHS are well-documented. SHS has been causally Although progress on adopting smoke-free legislation in most Eu­ associated with increased risk of lung cancer and myocardial infarction ropean countries has been made after the World Health Organization in adults (U.S. Department of Health and Human Services, 2006; Oberg (WHO) Framework Convention on Tobacco Control, outdoor smoke-free et al., 2011). Transient exposures, those that typically occur in outdoor regulations continue to be limited, at least in the WHO European region settings, might also trigger different biological mechanisms that could (Martinez et al., 2014). Besides, even when national or local measures negatively impact non-smokers’ health (Flouris et al., 2010). exist, legislation can be complex or not communicated sufficiently, via Children are more vulnerable to the harmful effects of SHS than signposting or other means, making enforcement and compliance a adults, as they have higher breathing rates and they inhale a greater challenge. mass of toxic material per body volume. A less mature immune system, a Data on SHS exposure in children’s outdoor play areas are scarce still-developing respiratory tract, and their dependence on the care­ and, to the best of our knowledge, SHS concentrations in such settings giver’s choice regarding smoke-free environments all further contribute have not been yet measured using objective markers. In the present to their susceptibility to tobacco smoke pollutants (Öberg et al., 2010). study, we aimed to describe SHS levels in children’s playgrounds in 11 There is evidence that SHS exposure in early life increases the risk for European countries by measuring airborne nicotine concentrations sudden infant death syndrome, middle ear infections, respiratory dis­ taking into account area-level SES, smoke-free regulations, the country’s orders, and asthma exacerbations (U.S. Department of Health and smoking prevalence and self-reported SHS exposure prevalence in Human Services, 2006; Öberg et al., 2010). playgrounds. There are marked social inequities in children’s exposure to SHS. Studies in high-income countries reveal socioeconomic factors to be 2. Methods closely related to children’s exposure at home; and confirm that social disparities in SHS exposure in early life persist over time among The study was conducted within the framework of the TackSHS households of different socioeconomic status (SES) (Moore et al., 2012; Project (Fernández et al., 2020). This is a cross-sectional study based on Pisinger et al., 2012; Gartner and Hall, 2013; Orton et al., 2014; Kuntz SHS objective environmental measurements. We measured SHS levels in and Lampert, 2016). Smoking restrictions in private spaces (mainly children’s playgrounds from major cities in 11 European countries: homes) are less common in more disadvantaged families (Moore et al., Bulgaria, France, Germany, Greece, Ireland, Italy, Poland, Portugal, 2012) and lower educated parents are more likely to smoke in the vi­ Romania, Spain, and the United Kingdom. For each of the countries, we cinity of their child (Kovess et al., 2013). Social disparities in children’s assessed SHS exposure in a convenience sample of 20 playgrounds. A SHS exposure go beyond the dwelling environment. Children in cars total of 220 observations were carried out between March 2017 and from deprived neighborhoods are more likely to be exposed to SHS while April 2018, excluding winter and summer months. Children’s play­ traveling (Montreuil et al., 2017). Additionally, a study assessing SHS in grounds were selected according to the neighborhood’s SES. Half of the different private and public settings found children’s SHS exposure to be measurements were done at sites belonging to the most deprived higher in some outdoor settings such as schools and nursery gates, with neighborhoods (below the 20th percentile of the SES distribution) and lower parental education and occupational social class (López et al., half to the most affluent neighborhoods (above the 80th percentile of the 2018). SES distribution). Neighborhood SES was established on the basis of There is a widely held belief that outdoor SHS exposure does not pose local synthetic deprivation indexes or other economic indicators, such as such a high risk to health as in indoor spaces. In confined areas, SHS residential rental prices, income of the neighborhood residents or rate of concentrations linger for hours after smoking has ceased, whereas out­ poverty by district depending on the country. Only playgrounds located door SHS concentrations diffuse much faster into the environment and outdoors and with slides, swings or other playing facilities were eligible. exposure periods are generally brief. Even so, field (CARB (California Air Measurements took place when there were at least five people, adults ResourcesBoard), 2005; Klepeis et al., 2007; Repace, 2007; Sureda et al., and/or children, in the playground area. To congregate the maximum 2013) and experimental (Klepeis et al., 2007; Repace, 2007) evidence number of people, fieldwork was mostly performed during weekdays has shown that outdoor SHS levels might be comparable to indoor SHS and at the end of school hours. levels while tobacco sources are active and dependent on certain con­ We monitored vapor-phase nicotine. Researchers taking part in the ditions of wind, source-receptor proximity, and the number of smokers environmental measurements received training on the use of monitoring present. Tobacco presence in outdoor child-related venues like play­ equipment and collecting additional tobacco-related observational data grounds raises concerns not only because children might be exposed to through specific forms. Guidance was provided in a written protocol for SHS but also because smoking might be perceived as a normal behavior environmental sampling. We took outdoor nicotine measurements by children, shaping their perceptions. In addition, cigarette butts are following a previously validated method (Hammond et al., 1987). 2 E. Henderson et al. Environment International 149 (2021) 105775 Samplers were 37-mm diameter plastic cassettes that contained a filter variables by Chi-squared test. All analyses were performed with the treated with sodium bisulfate. All nicotine samplers were coded and statistical package Stata 15. attached to air pumps (Sidekick, SKC Ltd., Dorset, UK) with a constant The TackSHS project was approved by the Clinical Research Ethics flow rate of 3 l/min. Air pumps were calibrated before and after moni­ Committee of the Bellvitge University Hospital (PR341/15) and this toring using a calibrator Defender 510 M (Mesa Labs, Lakewood, CO, study was specifically approved by the country’s local Ethics Commit­ USA). We assessed nicotine concentrations for 30 min through active tees (Supplementary Table 1). sampling. During nicotine measurements, observers were either still or walking around the setting. Nicotine measurements were taken inside 3. Results the playground area and/or in the immediate playground surroundings, at a maximum distance of 1 m. The Agència de Salut Pública de Barce­ Table 1 shows information about smoke-free regulations in countries lona Laboratory determined nicotine concentrations by gas included in the study. In 2017, nearly all European countries had some chromatography-mass spectrometry method. For every 20 nicotine form of national or local smoking bans for children’s playgrounds. TCS samples, one blank filter that had not been exposed was analyzed. We overall scores ranged from 81 out of 100 in the UK to 37 out of 100 in quantified the time-weighted average nicotine concentration (in μg/m3) Germany. by dividing the amount of nicotine extracted from the filter by the Overall, the median nicotine concentration in playgrounds was volume of air sampled (estimated flow rate times the minutes the filter below the LOQ of 0.06 μg/m3 (IQR: <0.06–0.125 μg/m3). Four countries had been exposed). This procedure has a limit of quantification (LOQ) of had median nicotine levels above the LOQ, with the highest levels found 5 ng per filter, which is equivalent to 0.06 μg/m3 of nicotine per 30 min in Romania (0.604 μg/m3 IQR: 0.063–2.354). There were detectable of exposure. To account for nicotine presence in playgrounds, concen­ levels of nicotine in 40.6% of the playgrounds. Among countries, there tration values were dichotomized using the LOQ as a cut-off point. was high variability in the proportion of playgrounds with nicotine Smell of smoke, the number of children and adults, and people presence. Most of the sites assessed in Greece (95.0%), France (90.0%), smoking inside and just around the playground area were collected at Romania (75.0%), and Bulgaria (73.7%) had detectable levels of nico­ three time points: at the beginning (0 min), after 15 min of sampling and tine (Table 2). at the end (30 min). We considered there was smell of smoke, people We found people smoking inside 19.6% of the playgrounds, and in smoking inside and people smoking in immediate vicinity to the play­ the immediate vicinity of the playground, in one out of four play­ ground when present at least in one of the three time points assessed. grounds. More than half of the playgrounds had cigarette butts visible The number of cigarette butts inside and just outside the playground inside (56.6%) and outside the playground area (74.4%) (Table 3). were also recorded. There was presence of cigarette butts in playgrounds As shown in Table 4, we found higher nicotine concentrations in when one or more cigarette butts were found inside or in the immediate playgrounds located in the most deprived neighborhoods (<0.06 μg/m3 vicinity to the playground. IQR: <0.06–0.153 μg/m3); in countries that scored below 50 in the TCS Different contextual variables were included as well. We checked for (0.090 μg/m3 IQR: <0.06–0.202 μg/m3); in countries with higher national and local smoking bans in children’s outdoor playgrounds and smoking prevalence (0.096 μg/m3 IQR: <0.06–0.270 μg/m3); and their implementation dates. For those playgrounds with smoking bans, higher self-reported SHS exposure prevalence in playgrounds (0.067 μg/ we looked at the years elapsed since the smoking ban was applied until m3 IQR: <0.06–0.176 μg/m3) (p < 0.05). Moreover, the proportion of the year samples were taken. We classified playgrounds into not regu­ playgrounds with airborne nicotine present was greater when countries lated, five or less years under a smoking ban and more than five years scored below 50 points in the TCS (69.5%), had higher current smoking under a smoking ban. We grouped countries according to the Tobacco prevalence (62.2%) and higher self-reported SHS exposure prevalence in Control Scale (TCS) overall score published in 2016 that quantifies the playgrounds (53.8%). In those playgrounds with no smoking bans, we implementation of tobacco control policies in European countries. The observed higher median nicotine levels (0.073 μg/m3 IQR: cut-off point for the TCS was set at the midpoint of the index score (50/ <0.06–0.155 μg/m3) than in playgrounds with recent smoking bans 100), following the country classification done at the TCS 2016 report (<0.06 μg/m3 IQR: <0.06–0.221 μg/m3) and playgrounds with smoking (Joossens and Raw, 2016). We also grouped countries based on their bans for more than 5 years (<0.06 μg/m3 IQR: <0.06–<0.06 μg/m3). current smoking prevalence (respondents were considered smokers The proportion of playgrounds with airborne nicotine present in the case when reported smoking at the time and had smoked at least 100 ciga­ of a smoking ban for more than five years (18.3%) was much lower than rettes during their lifetime); and on their playground self-reported SHS when playgrounds had recent smoking bans (47.1%) or no smoking bans exposure prevalence (considering exposure when non-smokers reported at all (52.7%). someone smoking at the place), both estimated through national surveys The presence of people smoking inside play areas was more common carried out within the TackSHS project on a representative sample of in playgrounds where smoking was either not banned (29.1%) or approximately 1000 people aged 15 years or older in each country recently banned (22.1%) than in countries with playground smoking (Fernández et al., 2020, Gallus et al., 2020). In the case of current bans for more than 5 years (6.7%) (p = 0.007). Smoking inside play­ smoking prevalence and self-reported SHS exposure prevalence in grounds was also more common when playgrounds were located in playgrounds, we used median values to generate categories (above or countries with a higher current smoking prevalence (26.1%) and higher equal/below). self-reported SHS exposure prevalence in playgrounds (25.2%) We excluded from the analyses one outlying nicotine measurement compared to those with lower smoking prevalence (12.0%) and lower as the calculated nicotine concentration was considered to be extremely self-reported SHS exposure prevalence in playgrounds (13.0%) high (>100 μg/m3) in outdoor settings. Given the skewed distribution of (p < 0.05). The presence of cigarette butts within the playground was nicotine, we used median and interquartile ranges (IQR) to describe higher in deprived neighborhoods (64.2%), in countries with no smok­ airborne nicotine concentrations. Samples with concentrations below ing bans in playgrounds (83.6%), lower overall scores in the TCS the LOQ of 0.06 μg/m3 were assigned half of this value. We provided raw (76.3%), with greater smoking prevalence (63.0%), and greater self- frequencies and percentages to describe nicotine presence and tobacco- reported SHS exposure prevalence in playgrounds (65.6%) (p < 0.05) related observational data. Nicotine levels were described according to (Table 5). SES, contextual variables and tobacco-related observational variables. Median nicotine concentrations and the percentage of presence of Tobacco-related observational data were also described according to airborne nicotine according to observational data related to tobacco SES and contextual variables. Nicotine concentrations were compared consumption are provided in Table 6. Median nicotine levels were using non-parametric U-Mann Whitney or Kruskal Wallis tests as 0.093 μg/m3 (IQR: <0.06–0.297 μg/m3) when smell of smoke was appropriate, and nicotine presence and tobacco-related observational noticeable, 0.115 μg/m3 IQR: <0.06–0.313 μg/m3) when there were 3 E. Henderson et al. Environment International 149 (2021) 105775 Table 1 Information on smoking regulations in children’s outdoor playgrounds and Tobacco Control Scale ranking in 11 European countries (2017–2018). Country City National smoking regulation up to 2017 Locala,b smoking regulation Tobacco Control Scale 2016 ranking (implementation year) (implementation year) (overall score) Bulgaria Sofia Banned (2012) N/A 20 (47/100) France Paris Banned (2015) N/A 4 (64/100) Germany Heidelberg Not regulated Banned (2005) 33 (37/100) Mannheim Not regulated Banned (2011) Greece Athens Not regulated Not regulated 31 (40/100) Ireland Dublin Not regulated Banned (2013) 2 (70/100) Italy Milano Not regulated Banned (2012) Varese Not regulated Banned (2017) 13 (51/100) Othersc Not regulated Not regulated Poland Warsaw Banned (2010) N/A 15 (50/100) Ciechanów Banned (2010) N/A Portugal Braga Not regulated Not regulated 15 (50/100) Romania Bucharest Banned (2016) N/A 7 (56/100) Spain Barcelona Banned (2011) N/A 8 (55/100) United Edinburgh Not regulated Banned (2016) 1 (81/100) Kingdom a City’s smoke-free regulation. b N/A: Not assessed as national regulation is in place. c Induno Olona, Arcisate, Bisuschio, Porto Cersio, Ponte Tresa, Buccinasco, Corsico, Cormano and Cesano Boscone. Table 2 Table 3 Airborne nicotine concentration (μg/m3) in children’s outdoor playgrounds by Tobacco-related variables in children’s outdoor playgrounds by country country (2017–2018). TackSHS Project. (2017–2018). TackSHS Project. Country N Median (μg/m3) Min (μg/ Max % nicotine Country N Smell of Smoking Smoking Butts Butts (IQR) m3) (μg/m3) presence (n) smokea inside outsidea,b inside outsideb % (n) % (n) % (n) % (n) % (n) All 219 <0.06 <0.06 6.038 40.6 (89) (<0.06–0.125) All 219 18.1 19.6 (43) 24.6 (49) 56.6 74.4 Bulgaria 19 0.090 <0.06 0.708 73.7 (14) (36) (124) (163) (<0.06–0.125) Bulgaria 19 36.8 (7) 15.8 (3) 42.1 (8) 68.4 94.7 (18) France 20 0.190 <0.06 2.700 90.0 (18) (13) (0.113–0.305) France 20 – 55.0 (11) – 0.0 (0) 40.0 (8) Germany 20 <0.06 <0.06 0.422 40.0 (8) Germany 20 25.0 (5) 20.0 (4) 20.0 (4) 80.0 80.0 (16) (<0.06–0.085) (16) Greece 20 0.196 <0.06 0.688 95.0 (19) Greece 20 35.0 (7) 45.0 (9) 40.0 (8) 80.0 90.0 (18) (0.099–0.289) (16) Ireland 20 <0.06 <0.06 0.081 5.0 (1) Ireland 20 5.0 (1) 15.0 (3) 30.0 (6) 55.0 95.0 (19) (<0.06–<0.06) (11) Italy 20 <0.06 <0.06 0.206 25.0 (5) Italy 20 25.0 (5) 25.0 (5) 35.0 (7) 65.0 75.0 (15) (<0.06–<0.06) (13) Poland 20 <0.06 <0.06 <0.06 0.0 (0) Poland 20 5.0 (1) 0.0 (0) 5.0 (1) 25.0 (5) 70.0 (14) (<0.06–<0.06) Portugal 20 15.0 (3) 10.0 (2) 15.0 (3) 95.0 100 (20) Portugal 20 <0.06 <0.06 0.616 25.0 (5) (19) (<0.06–0.065) Romania 20 25.0 (5) 30.0 (6) 30.0 (6) 50.0 45.0 (9) Romania 20 0.604 <0.06 6.038 75.0 (15) (10) (0.063–2.354) Spain 20 10.0 (2) 0.0 (0) 20.0 (4) 85.0 95.0 (19) Spain 20 <0.06 <0.06 0.194 15.0 (3) (17) (<0.06–<0.06) UK 20 0.0 (0) 0.0 (0) 10.0 (2) 20.0 (4) 35.0 (7) UK 20 <0.06 <0.06 0.150 5.0 (1) p-Valuec 0.009 <0.0001 0.070 <0.0001 <0.0001 (<0.06–<0.06) a p-Value 0.0001a <0.0001b Total numbers do not add 219 because of missing values. b Just around the playground at a maximum distance of 1 m. 3 Note: IQR, Interquartile Range. Limit of Quantification (LOQ): 0.06 µg/m . c Chi-squared test. a Kruskal-Wallis test. b Chi-squared test. in playgrounds, the country’s level of implementation of tobacco control policies, national smoking prevalence and self-reported SHS exposure people smoking inside, and < 0.06 μg/m3 (IQR: <0.06–0.222 μg/m3) prevalence in playgrounds. when there were people smoking outside (p < 0.05). In such cases, the Child-related settings have been widely recognized as a priority in percentage of playgrounds with detectable nicotine levels were 66.7%, tobacco control by health and political authorities, especially after The 74.4% and 49.0%, respectively (p < 0.05). Median nicotine concentra­ WHO Framework Convention on Tobacco Control entered into force in tions and nicotine presence were lower when there were no cigarette 2005, and the following MPOWER measures (2008), and the European butts outside the playing area (p < 0.05). Council Recommendation on smoke-free environments were released (2009). However, very few objective data exist on the exposure at these 4. Discussion outdoor public settings. The present results show there was airborne nicotine in roughly one- This study is the first to report on SHS levels in outdoor children’s third of the playgrounds studied. Our data also indicate there were playgrounds in 11 European countries. Our data reveal that SHS expo­ discarded cigarette butts in nearly three out of five playgrounds and sure is present in outdoor playgrounds, with considerable differences in people smoking in one out of five playgrounds across Europe. These exposure by area-level socioeconomic status, presence of smoking bans findings are important for several reasons. First, there is no risk-free 4 E. Henderson et al. Environment International 149 (2021) 105775 Table 4 Airborne nicotine concentration (μg/m3) in children’s outdoor playgrounds by area-level socioeconomic status, smoke-free regulation in playgrounds, Tobacco Control Scale overall score, national smoking prevalence, and national self-reported secondhand smoke exposure prevalence in playgrounds (2017–2018). TackSHS Project. Contextual factors N Median (μg/m3) (IQR) p-Valuea Min (μg/m3) Max (μg/m3) % nicotine presence (n) p-Valueb All 219 <0.06 (<0.06–0.125) <0.06 6.038 40.6 (89) SES High 110 <0.06 (<0.06–0.087) 0.036 <0.06 4.367 34.6 (38) 0.065 Low 109 <0.06 (<0.06–0.153) <0.06 6.038 46.8 (51) Year since implementation of ban >5 60 <0.06 (<0.06–<0.06) <0.06 0.422 18.3 (11) ≤5 104 <0.06 (<0.06–0.221) 0.0001 <0.06 6.038 47.1 (49) <0.0001 Not regulated 55 0.073 (<0.06–0.155) <0.06 0.688 52.7 (29) TCS overall score ≥50 160 <0.06 (<0.06–0.091) <0.0001 <0.06 6.038 30.0 (48) <0.0001 <50 59 0.090 (<0.06–0.202) <0.06 0.708 69.5 (41) Smoking prevalence (2017–18)c <31% 100 <0.06 (<0.06–<0.06) <0.0001 <0.06 0.422 15.0 (15) <0.0001 ≥31% 119 0.096 (<0.06–0.270) <0.06 6.038 62.2 (74) SHS exposure prevalence in playgrounds (2017–18)d <42.4% 100 <0.06 (<0.06–<0.06) 0.001 <0.06 6.038 25.0 (25) <0.0001 ≥42.4% 119 0.067 (<0.06–0.176) <0.06 2.700 53.8 (64) Note: SES, socioeconomic status; TCS, Tobacco Control Scale; SHS, secondhand smoke. Limit of Quantification (LOQ): 0.06 µg/m3. a Mann-Whitney U test or Kruskal-Wallis test. b Chi-squared test. c National smoking prevalence (median): <31 (Germany, Ireland, Italy, Poland, UK) ≥ 31 (Bulgaria, France, Greece, Portugal, Romania, Spain) d National SHS exposure prevalence in playgrounds (median): <42.4 (Germany, Ireland, Poland, Romania, UK) ≥ 42.4 (Bulgaria, France, Greece, Italy, Portugal, Spain) threshold of SHS exposure, a well-known human carcinogen (IARC, nicotine concentrations and presence were lowest when playgrounds 2004). In consequence, a safe level of exposure for children to be pro­ had been covered by smoking bans for more than 5 years. Moreover, the tected cannot be established. Second, even short exposure periods could percentage of people smoking in these playgrounds was half the corre­ be harmful to health (Flouris et al., 2010). Third, outdoor playgrounds sponding percentage in playgrounds not covered by smoking bans. are spaces designed for children, who are particularly vulnerable to the Despite these findings, this study reveals presence of airborne nicotine, health effects of SHS (Öberg et al., 2010). Fourth, cigarette butts are a people smoking, and other signs related to tobacco consumption inside commonly littered item leaving children exposed to the risk of swal­ some playgrounds where smoking is already forbidden. This lack of law lowing toxic substances, as well as increasing the costs of playground enforcement is especially noticeable in countries with more recent re­ maintenance. Finally, children could normalize smoking behaviors strictions, proving the importance of adopting measures that strengthen when smoking in their surroundings is perceived as a socially accepted law adherence the first years a smoking ban is implemented. Even so, norm, which therefore might encourage smoking initiation later in life our results might also suggest that smoking bans over time help raise (Bayer and Bachynski, 2013). awareness of the health impacts of SHS exposure and reduce social We have found socioeconomic inequalities in the exposure to SHS at acceptability of smoking. To our knowledge, no previous work has playgrounds. Our results suggest there is higher exposure to SHS in more described airborne nicotine levels in playgrounds according to smoking deprived areas, indicating exposure is not only to be seen as an indi­ bans. Nevertheless, the impact of smoke-free rules has been reported in vidual responsibility but it is also related to contextual factors. These outdoor park areas where young adults, regardless of their smoking results are in line with other findings from private settings, such as status, perceived greater difficulty to smoke when smoking bans were in homes. Children’s exposure to SHS at home has been linked to com­ place (Klein et al., 2012). We also found that playgrounds without posite measures of SES as well as individual-level socioeconomic in­ smoking regulations had a greater presence of cigarette leftovers, indi­ dicators like parental income, education, and occupational social class cating a likely higher tobacco consumption level in those sites. However, (Orton et al., 2014; López et al., 2018). While not required by any of the the presence of cigarette butts is probably also affected by playground laws promoting smoke-free environments, evidence points to an maintenance increased willingness to adopt smoke-free private spaces when smoke- Playgrounds located in countries with greater current smoking free policies are implemented (Mons et al., 2013). However, unequal prevalence rates had higher levels of airborne nicotine, and a greater reactions to population-based strategies can also exacerbate health in­ presence of smokers and cigarette butts. Differences in exposure were equalities, as has been shown after the introduction of smoking bans in also seen and measured according to the scope and degree of imple­ enclosed public places and workplaces and SHS exposure at households mentation of tobacco control policies in Europe. Countries with less with children in three UK countries (Moore et al., 2012). Therefore, developed tobacco control efforts, as indicated by lower TCS overall policies tackling SHS exposure at outdoor settings should come along scores, had higher levels and greater presence of SHS exposure at with other public health actions that target deprived areas and disad­ playgrounds. These results are in agreement with what has been found vantaged groups, as could be rigorous monitoring of the implementation in indoor settings where exposure to SHS was less likely with increased stages of new policies; outreach efforts to raise the awareness of the scores for the smoke-free tobacco component of the TCS in bars, res­ harms of tobacco presence in child-related settings; and improving the taurants, and workplaces; and more likely with greater smoking prev­ access to smoking cessation services. In any case, all measures seeking to alence in bars and restaurants across Europe (Filippidis et al., 2016). reduce SHS exposure should be framed within structural policies aiming Median nicotine levels and nicotine presence were higher when to decrease social inequalities. cigarette butts were not found outside the playground area. This Our findings show an association between places frequented by discrepancy might be explained by the fact that the presence of cigarette children with smoking bans and lower exposure to SHS. Airborne butts, in contrast to the presence of smell of tobacco smoke or people 5 E. Henderson et al. Environment International 149 (2021) 105775 Table 5 implementation of tobacco control policies, smoking prevalence and Tobacco-related variables in children’s outdoor playgrounds by area-level so­ self-reported SHS exposure prevalence in playgrounds. Second, to cioeconomic status, smoke-free regulation in playgrounds, Tobacco Control establish the neighborhood’s SES, each country used local independent Scale overall score, national smoking prevalence, and national self-reported indexes. This approach could result in differences in SES classification secondhand smoke exposure prevalence in playgrounds (2017–2018). between countries. However, by using country specific indexes we more TackSHS Project. accurately determined SES in each neighborhood and synthetic depri­ Contextual N Smell Smoking Smoking Butts Butts vation indicators were applied when available. Moreover, to overcome factors of inside outsidea,b inside outsideb this limitation, we selected neighborhoods below the 20th percentile of smokea % (n) % (n) % (n) % (n) % (n) the SES distribution and above the 80th percentile of the SES distribu­ tion. Another limitation is that fieldwork was conducted in one or more All 219 18.1 19.6 (43) 24.6 (49) 56.6 74.4 cities per country and might not necessarily be representative of the (36) (124) (163) whole country. Finally, many researchers were involved in the field­ SES work. Thus, we attempted to minimize the potential variability in data High 110 13.0 15.5 (17) 22.0 (22) 49.1 71.8 (13) (54) (79) collection by training and by providing a detailed protocol for envi­ Low 109 23.2 23.9 (26) 27.3 (27) 64.2 77.1 ronmental sampling to all researchers. (23) (70) (84) This is a multi-country study that includes diverse cities, represent­ p- 0.061 0.118 0.388 0.024 0.374 ing geographical, legislative and cultural variations across Europe. It is Valuec also the first study that objectively measures SHS exposure in play­ Years since implementation grounds by monitoring airborne nicotine, a tobacco-specific constituent >5 60 13.3 6.7 (4) 15.0 (9) 63.3 81.7 (Apelberg et al., 2013). The procedure for nicotine sampling has been (8) (38) (49) ≤5 104 16.7 22.1 (23) 28.6 (24) 38.5 61.5 previously validated (Hammond et al., 1987) and several studies have (14) (40) (64) used this tracer previously to estimate SHS exposure in outdoor settings Not 55 25.5 29.1 (16) 29.1 (16) 83.6 90.9 (López et al., 2012; Fu et al., 2016). Furthermore, we examined SHS regulated (14) (46) (50) exposure as a function of a wide range of contextual variables, providing p- 0.218 0.007 0.117 <0.0001 <0.0001 new information about factors influencing SHS exposure in outdoor Valuec playgrounds at a local and national level. TCS overall score (2016) In conclusion, this study shows evidence of SHS exposure in chil­ 160 12.1 16.9 (27) 20.7 (29) 49.4 69.4 dren’s outdoor playgrounds in Europe. Our findings provide a clear ≥50 (17) (79) (111) <50 59 32.2 27.1 (16) 33.9 (20) 76.3 88.1 message to policy makers as legislation and tobacco control policies (19) (45) (52) banning smoking in playgrounds are needed. In addition, in those p- 0.001 0.090 0.049 <0.0001 0.005 countries where these bans already exist, better enforcement is required. c Value Furthermore, other public health interventions that target a reduction in Smoking prevalence (2017–18)d SHS exposure, especially targeting deprived and vulnerable groups, <31% 100 12.0 12.0 (12) 20.0 (20) 49.0 71.0 should be conducted from an equity perspective in order to decrease (12) (49) (71) inequalities. ≥31% 119 24.2 26.1 (31) 29.3 (29) 63.0 77.3 (24) (75) (92) p- 0.025 0.009 0.128 0.037 0.286 Funding sources c Value SHS exposure prevalence in playgrounds (2017–18)e This project has received funding from the European Union’s Hori­ <42.4% 100 12.0 13.0 (13) 19.0 (19) 46.0 65.0 zon 2020 research and innovation program under grant agreement No (12) (46) (65) 681040. MJ and XC were partly supported by the Ministry of Univer­ 119 24.2 25.2 (30) 30.3 (30) 65.6 82.4 sities and Research, Government of Catalonia under grant ≥42.4% (24) (78) (98) p- 0.025 0.023 0.064 0.004 0.003 2017SGR1526. The Tobacco Control Research Group at IDIBELL is Valuec partly supported by Ministry of Universities and Research, Government of Catalonia (2017SGR319). EF is partly supported by the Instituto Note: SES, socioeconomic status; TCS, Tobacco Control Scale; SHS, secondhand smoke. Carlos III and co-funded by the European Regional Development Fund a Total numbers do not add 219 because of missing values. (FEDER) (INT16/00211 and INT17/00103), Government of Spain. The b Just around the playground at a maximum distance of 1 m. work of SG was partially supported by the Italian League Against Cancer c Chi-squared test. (LILT, Milan). d National smoking prevalence (median): <31 (Germany, Ireland, Italy, Poland, UK) ≥ 31 (Bulgaria, France, Greece, Portugal, Romania, Spain) 6. Disclaimer e National SHS exposure prevalence in playgrounds (median): <42.4 (Ger­ many, Ireland, Poland, Romania, UK) ≥ 42.4 (Bulgaria, France, Greece, Italy, This manuscript was developed by the TackSHS Project Consortium Portugal, Spain) and does not necessarily reflect the views of the European Commission. The European Commission is not responsible for any use that may be smoking, might not strictly relate to the moment airborne nicotine levels made of the information that contains in this document. were being monitored but capture tobacco consumption beyond the monitoring period. CRediT authorship contribution statement In interpreting these results, several limitations should be acknowl­ edged. We have used a convenience sample of playgrounds, which might Elisabet Henderson: Formal analysis, Writing - original draft, lead to a potential selection bias or could undermine the study’s external Visualization. Xavier Continente: Conceptualization, Investigation, validity. Despite this, the nature of our sample did not interfere with the Validation, Writing - review & editing. Esteve Fernández: Investiga­ main objective of the study, which was to assess potential differences in tion, Writing - review & editing, Conceptualization, Project adminis­ SHS exposure at children’s outdoor playgrounds according to contextual tration. Olena Tigova: Investigation, Writing - review & editing, Project variables. Data have been analyzed grouping the selection of play­ administration. Nuria Cortés-Francisco: Investigation, Writing - re­ grounds taking into account the neighborhood’s SES, the country’s view & editing. Silvano Gallus: Investigation, Writing - review & 6 E. Henderson et al. Environment International 149 (2021) 105775 Table 6 Airborne nicotine concentrations (μg/m3) and tobacco-related variables in children’s outdoor playgrounds in 11 European countries (2017–2018). TackSHS Project. Tobacco-related variables N Median (μg/m3) (IQR) p-Valuea Min (μg/m3) Max (μg/m3) % nicotine presence (n) p-Valueb c Smell of smoke Yes 36 0.093 (<0.06–0.297) <0.0001 <0.06 4.161 66.7 (24) <0.0001 No 163 <0.06 (<0.06–0.079) <0.06 6.038 28.8 (47) People smoking inside the playground Yes 43 0.115 (<0.06–0.313) <0.0001 <0.06 4.161 74.4 (32) <0.0001 No 176 <0.06 (<0.06–0.094) <0.06 6.038 32.4 (57) People smoking outside the playgroundc,d Yes 49 <0.06 (<0.06–0.222) 0.031 <0.06 1.868 49.0 (24) 0.025 No 150 <0.06 (<0.06–0.087) <0.06 6.038 31.3 (47) Presence of butts inside the playground Yes 124 <0.06 (<0.06–0.122) 0.433 <0.06 4.367 38.7 (48) 0.507 No 95 <0.06 (<0.06–0.158) <0.06 6.038 43.2 (41) Presence of butts outside the playgroundd Yes 163 <0.06 (<0.06–0.104) 0.009 <0.06 2.700 36.8 (60) 0.049 No 56 0.063 (<0.06–0.308) <0.06 6.038 51.8 (29) Note: Limit of Quantification (LOQ): 0.06 µg/m3. a Mann-Whitney U test. b Chi-squared test. c Total numbers do not add 219 because of missing values. d Just around the playground at a maximum distance of 1 m. editing. Alessandra Lugo: Investigation, Writing - review & editing. Sheila Keogan, Hannah Byrne. Sean Semple: Investigation, Writing - review & editing. Rachel Hellenic Cancer Society – George D. Behrakis Research Lab (HCS), O’Donnell: Investigation, Writing - review & editing. Luke Clancy: Greece: Panagiotis Behrakis, Anna Tzortzi, Constantine Vardavas, Ver­ Investigation, Writing - review & editing. Sheila Keogan: Investigation, gina Konstantina Vyzikidou, Gerasimos Bakelas, George Mattiampa. Writing - review & editing. Ario Ruprecht: Investigation, Writing - re­ Fondazione IRCCS Istituto Nazionale dei Tumori (INT), Italy: Roberto view & editing. Alessandro Borgini: Investigation, Writing - review & Boffi, Ario Ruprecht, Cinzia De Marco, Alessandro Borgini, Chiara Ver­ editing. Anna Tzortzi: Investigation, Writing - review & editing. Ver­ onese, Martina Bertoldi, Andrea Tittarelli. gina K Vyzikidou: Investigation, Writing - review & editing. Giuseppe Istituto per lo Studio, la Prevenzione, e la Rete Oncologica (ISPRO), Italy: Gorini: Investigation, Writing - review & editing. Angel López-Nicolás: Giuseppe Gorini, Giulia Carreras, Barbara Cortini, Simona Verdi, Alessio Investigation, Writing - review & editing. Joan B Soriano: Investiga­ Lachi, Elisabetta Chellini. tion, Writing - review & editing. Gergana Geshanova: Investigation, Polytechnic University of Cartagena (UPCT), Spain: Ángel López Nic­ Writing - review & editing. Joseph Osman: Investigation, Writing - olás, Marta Trapero-Bertran, Daniel Celdrán Guerrero. review & editing. Ute Mons: Investigation, Writing - review & editing. European Network on Smoking and Tobacco Prevention (ENSP), Krzysztof Przewozniak: Investigation, Writing - review & editing. José Belgium: Cornel Radu-Loghin, Dominick Nguyen, Polina Starchenko. Precioso: Investigation, Writing - review & editing. Ramona Brad: Hospital Universitario La Princesa (IISP), Spain: Joan B Soriano, Julio Investigation, Writing - review & editing. Maria J. López: Conceptu­ Ancochea, Tamara Alonso, María Teresa Pastor, Marta Erro, Ana Roca, alization, Investigation, Writing - review & editing, Project adminis­ Patricia Pérez, Elena García Castillo. tration, Funding acquisition. Appendix A. Supplementary material Declaration of Competing Interest Supplementary data to this article can be found online at https://doi. The authors declare that they have no known competing financial org/10.1016/j.envint.2020.105775. interests or personal relationships that could have appeared to influence the work reported in this paper. References Apelberg, B.J., Hepp, L.M., Avila-Tang, E., Gundel, L., Hammond, S.K., Hovell, M.F., Acknowledgements et al., 2013. Environmental monitoring of secondhand smoke exposure. Tob. Control 22 (3), 147–155. https://doi.org/10.1136/tobaccocontrol-2011-050301. 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