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Cigarette butt littering in city streets: a new methodology for studying and results
  1. Vimal Patel,
  2. George W Thomson,
  3. Nick Wilson
  1. Department of Public Health, University of Otago, Wellington, New Zealand
  1. Correspondence to Dr Nick Wilson, Department of Public Health, Wellington School of Medicine, University of Otago, PO Box 7343, Wellington South, Wellington 6021, New Zealand; nwilson{at}


Objectives The objectives of the present work were to (a) develop a relatively simple single-observer method for data collection on cigarette butt discarding; and (b) quantify cigarette butt discarding behaviour in city streets.

Methods A method was developed, piloted and refined (with interobserver assessment). Cigarette butt discarding was systematically observed by a single data collector while walking a continuous circuit of busy downtown streets in a capital city (Wellington, New Zealand).

Results The final method appeared feasible in this setting and seemed efficient (at 5.5 discarding events observed per hour). A clear majority (76.7%; 95% CI 70.8 to 82.0%) of the 219 smokers observed littered their cigarette butts. Butt littering was more common for those who did not extinguish their cigarette (94.4% vs 4.5%, p=0.003). Butt littering was more common in the evening versus lunchtime periods of observation (85.8% vs 68.1%, p=0.002, logistic regression analysis). Overall, most smokers (73.5%) did not extinguish their butts and some placed lit butts in bins (constituting a risk of bin fires). The context for this littering was a high density of rubbish bins on this circuit with a mean of 3.5 bins being in view and with a bin every 24 m on average.

Conclusions Butt littering behaviour appears to be the norm among smokers in this urban setting, even though rubbish bins were ubiquitous. One solution is stronger enforcement of littering laws. Nevertheless, in a society with a national smokefree goal (by year 2025 for New Zealand), it would probably be more logical and cost effective to move to smokefree policies for major city streets, which are used in a number of jurisdictions internationally.

  • Public policy
  • tobacco control policy
  • taxation and price
  • economics
  • end game
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The global human population smokes around 5.6 trillion cigarettes annually from which the cigarette butt waste is estimated to comprise 2.8 billion litres by volume.1 Cigarette butts also comprise a substantial proportion of all litter (eg, 46% in an Australian study2; and 27% in an international coastal cleanup3). Of particular relevance to local authorities is that discarded cigarette butts increase litter removal costs, detract from the appearance of towns and cities, pose fire and safety risks, and are an environmental problem in that butts can be washed into waterways and marine areas, where they pose risks to aquatic life.4 ,5 Despite the size of the butt litter problem, we are aware of only one observational study of smokers that quantified cigarette butt discarding behaviour6 (and some of its determinants). It involved multiple observers located in stationary sites (eg, in a public seating area or inside a parked car) and found a butt littering level of 65% among 530 smokers.

In New Zealand, tobacco-related litter is also an important problem, especially since most major cities surround harbours and storm-water drainage carries butt litter into these. Cigarette butts are also a fire hazard in urban areas (work by us has revealed retailer reports of extinguishing bin fires outside their shops).7

All public and workplace buildings in New Zealand must be smokefree by law, so lit cigarettes should not be taken into buildings in downtown areas (and we have never observed this in the past decade). In the capital city, Wellington, there is a fine for general littering, but only 129 fines were imposed in 2008,8 the most recent year for which data are available (and with no specific data on fines for butt littering). Smoking on the streets is common however, with a previous study on a circuit of Wellington streets (the exact streets as in this study being reported) finding that a person walking along passes around 7 people smoking every 10 min on average (based on 923 smokers observed over 21 h).9

Given this background, we aimed to extend the slim literature by documenting butt littering behaviour in the New Zealand setting. To perform this efficiently we also aimed to develop a method that was simple and required only a single observer.


A structured observation method was devised, then trialled on 22 September 2011, with subsequent refinement. The final method used involved a single observer walking both sides of two streets in a continuous 1.58 km circuit in the central business district of the capital city of New Zealand (Wellington) (see: for the circuit map). The observer walked on one side of the pavement until the first active smoker was observed walking either in front of them or past them. At that point the smoker was discreetly followed (maintaining a minimum distance of at least 5 m) and continuously observed until the point of butt discarding (even if they left the designated circuit streets). To minimise the chance of a smoker realising that they were being observed, the observer only attended to those people smoking who were walking and could not easily see the observer (ie, not standing/sitting or waiting at a bus stop). If a walking smoker did suddenly stop (eg, to use an ATM), the observer discreetly stopped some distance away and became preoccupied with some typical activity (eg, mobile phone use). Data were also collected on the number of litter bins on the circuit of streets.

Data collection occurred on the Fridays and Saturdays of 5 weeks (of which 4 weeks were continuous) from October to November 2011 (mid/late spring in New Zealand). It occurred on two periods on these 10 days: lunchtime (12:00 h to 14:00 h) and evening (18:00 h to 20:00 h). Ethical approval for this research was obtained through the ethics approval process of the University of Otago.

Data were entered into a preformatted spreadsheet program that had been loaded onto a handheld digital device (an iPod Touch). Data were compiled in Microsoft Excel (Microsoft, Redmond, Washington, USA) and analysed in Stata (Stata Corp, College Station, Texas, USA).

For two observation periods (4 h total), a secondary observer (NW) accompanied and walked the same route as the lead observer (VP). Both observers then independently collected data on smokers and how they disposed of their cigarette butt.


Evaluation of the method

The single-observer method appeared feasible, at least in this type of setting. It also seemed to be relatively efficient with 219 butt discarding events observed in 40 h (ie, 5.5 per hour). It was also completely discreet and at no point did the observers seem to be noticed or were asked what they doing. The sensitivity of the lead observer's (VP) identification of smokers to a secondary observer (NW; who accompanied and walked the same route as the lead observer) was 92.9% (26/28). For jointly observed discarding events, the agreement on the classification of littering/non-littering was high at 95.4% (21/22).

Results of the observational study

No smokers who were followed entered a building while still carrying their cigarette. Of the 219 discarding events observed (table 1), 76.7% were in inappropriate locations on pavement and in gutters (ie, littering). Some littering occurred directly beside rubbish bins with butt receptacles. Cigarette butt littering was significantly more common among those who did not extinguish their cigarette (94.4%) versus those who extinguished with their hand (4.5%; RR=20.8; p<0.001). Similarly, for smokers observed in the evening versus lunchtime (85.8% vs 68.1%; RR=1.26; p=0.002, table 1). A logistic regression model that adjusted for sex of the smoker, time of discarding (lunchtime or evening) and day of discarding (Friday or Saturday) also showed that the proportion of littering was more common during evening than lunchtime periods (85.9% vs 68.1% littered; p=0.003; details available from the authors). Roll-your-own (RYO) tobacco smokers were slightly more likely to litter than those smoking manufactured cigarettes, but this was not statistically significant. There were no other statistically significant differences in butt littering by the other variables for which data were collected (table 1).

Table 1

Observed cigarette butt discarding behaviour by a single observer on a continuous circuit of downtown streets in central Wellington, New Zealand during October and November 2011

The large majority (73.5%) of smokers did not extinguish their butts and 3.7% (6/161) of these discarded directly into bins (representing a risk of bin fires). Discarding butts directly into storm-water drains that flow into the harbour was also observed (3.7%, 8/219), along with ‘blind tossing’ (ie, the walking smoker tossing the butt behind them and not observing its flight path). All those who extinguished burning butts by foot pressure (n=14) did not then discard the butt appropriately.

Rubbish bin density

There was a mean of one bin every 24 m on the pavements of the 1.58 km circuit of streets (n=66). Of these, all but one (98.5%) contained dedicated cigarette butt receptacles (two per bin). At each of 12 approximately equal divisions on the circuit, a mean of 3.5 bins were visible (range: 1 to 8).


We developed, trialled and used a single-observer method to quantify cigarette butt discarding behaviour in an urban setting. The main differences between the only previous published butt discarding study method6 and ours, are that we covered a wider geographical area for identifying smokers (not using a stationary observation point), moving smokers were followed to the point of discarding and a single observer was used (with both of the latter designed to enhance efficiency of data collection).

Quality of the method

This method appeared to be feasible in this particular city setting with good interobserver reliability. Furthermore, it might be reasonably applicable to other urban settings with pedestrian areas. Nevertheless, we note that the method is untested in cities that are significantly busier, have tightly enforced litter laws, do not have smokefree indoor places and which are less safe. This method appears to be more time efficient than paired stationary observers in the previous study,6 at 5.5 observations of butt discarding per hour versus <0.5 events per observer hour. However, that former study collected additional variables such as the discarding location. Our method could be modified to collect extra information such as location, particularly if pairs of observers were used. It also allows for collecting littering behaviour in a wider range of street settings than stationary observational approaches.

The major methods limitation is probably the inclusion of only smokers who were walking (and exclusion of stationery smokers). While this was done for what we consider good reasons (to minimise influencing smoker behaviour), it is plausible that walking smokers have different butt discarding levels. Despite the method being completely discreet and feeling safe to the observers, to further minimise any potential ethical or safety concerns modifications could be made. These include using female/male or female/female observer pairs, selecting only the safest parts of the city and focusing only on busy working week days (eg, around lunchtime). A further modification may be a random selection from a series of successive smokers observed, and this may improve the validity of the method (albeit taking more time to obtain a reasonable sample).

Interpretation of the main results

Of the 219 smokers observed, the large majority (77%) littered their cigarette butts. This level is higher than the 65% in the only other study we know of (ie, one in the US, albeit with a different method6). If littering patterns vary by education or income (and we do not have data on this is in the New Zealand setting), our finding may be an underestimate of the national butt littering level for New Zealand. This is because these central city smokers were probably better educated and wealthier than the national average for smokers given their low pattern of RYO usage (21%), compared to majority RYO use at the national level.10

We can only speculate as to the reasons for the higher proportion of littering in the evening (vs lunchtime) and on Saturdays (vs Fridays). One possibility is the reduced social inhibition towards littering outside of working/business hours and/or disinhibition from drugs such as alcohol (this part of the city has many pubs and restaurants selling alcohol). Another reason might be that non-office workers visiting this area outside ‘work hours’ might also be more likely to be smokers. Finally, it is possible that some smokers might fear being fined for littering during certain times more than others, but we doubt that this would be particularly important.

Possible policy implications

This study found that littering was occurring in the context of bins being ubiquitous on these downtown city streets. Hence it seems unlikely that additional rubbish bins on the streets would cost-effectively reduce the butt littering problem. We also suspect that further efforts to educate smokers would not be cost effective (even though this might continue to be the preferred approach promoted by anti-litter groups in New Zealand11 and the tobacco industry which supports such groups7).

A possible solution may be stronger enforcement of littering laws and/or larger fines for butt littering. Nevertheless, in a society with a national smokefree goal (which is 2025 for New Zealand12), it would probably be more logical and cost effective to just make all major downtown city streets smokefree. This could be accompanied with designated smoking areas located away from pedestrian flows or buildings (as a temporary measure until the smokefree goal is achieved). In addition to the usual advantages of reducing butt litter (see Introduction), this approach would: (1) help to reduce non-smokers being exposed to the nuisance and health effects of secondhand smoke; and (2) help to denormalise smoking, with the consequent potential benefit of lower smoking uptake and increased quitting.13 Indeed, smokefree street policies have now started to appear in other parts of New Zealand,14 ,15 and smokefree street laws are used in a number of jurisdictions internationally.16–18

Finally, public health advocates could consider using this simple and inexpensive method to collect more data so as to inform local policy making around smokefree outdoor areas.

What this paper adds

  • We were able to develop a relatively efficient single-observer method for documenting the cigarette butt littering proportion.

  • In the central city area of the capital city we studied, a clear majority (77%) of the 219 smokers observed littered their cigarette butts.

  • Given the fact that littering was occurring in the context of a high density of litter bins, these data support more rigorous interventions such as making downtown city streets smokefree.


The authors thank the National Heart Foundation for funding assistance with this study (Grant 1497). However, the funder had no role in the decision to publish or in the content of this article.


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  • Funding Funding was received from the National Heart Foundation.

  • Competing interests None.

  • Ethics approval Ethics approval was provided by University of Otago.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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