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problem is and what the likely outcomes are if we continue onour present course. This is also true of much work conductedby environmental scientists. To wit, ecological risk assess-ments or studies on the localized effects of hazardous wastesites are likely to seem trivial when hundreds of billions ofdollars are being spent on seawalls to protect coastal citiesfrom high tides and storm surges on top of the 2- to 7-foot sealevel rise likely for this century (Climate Central 2012).

Finally, Cairns calls on us to exhibit humility in the face ofthe ecological meltdown now underway. Humility, however,will not prevent the ‘‘increasingly hostile, unstable, uninhabit-able planet’’ that will result if no actions are taken. Althoughgreenhouse gases already in the system assure serious environ-mental consequences, it appears that there is still time, howeverfleeting, to prevent worst-case scenarios. It is thereforeincumbent on those truly interested in preserving biodiversityand decreasing the effects of climate change to minimize theirhypocrisy. Want nature? Walk, bike, or use public trans-portation to commute to school or work. Drive fuel-efficientvehicles (>50mpg), but drive less. Turn everything, includingcomputers, off when not in use. Use less, waste less, fly less,conserve more, recycle everything possible, and supportenvironmental organizations that work to change public policy.Above all else, stop breeding! Those who have bred in the last20 to 25 years, especially those from first-world countries whereper capita environmental impact greatly exceeds that of lessdeveloped countries, bear an extra responsibility to minimizetheir carbon footprint. If Society of Environmental Toxicologyand Chemistry members, who are ostensibly in favor ofpreserving biodiversity, will not transform their lifestyles toeffect positive changes, how can we expect others to do so?

REFERENCESBrown LR, Durning A, Flavin C, French H, Jacobson J, Lowe M, Postel S, Renner M,

Starke L, Young J. 1990. State of the world. New York (NY): W.W. Norton. 253

pp.

Cairns J Jr. 2012. Letter to the editor: A call for humility and an end to humankind’s

disruption of evolutionary processes. Integr Environ Assess Manag 8:2–3.

Climate Central. 2012. Sea level projections. [cited 5 May 2012]. Available from:

http://sealevel.climatecentral.org/basics/projections

Ehrlich PR, Ehrlich AH. 1990. The population explosion. New York (NY): Simon &

Schuster. 330 pp.

Hurlbert S. 2011. Is AAAS oblivious to U.S. overpopulation and its consequences?

Or is it just another censor? Soc Contract 22:67–71.

McKibben B. 1989. The end of nature. New York (NY): Random House. 195 pp.

Meyerson F. 2009. Population, biodiversity, and human well-being. Front Ecol

Environ 7:511.

THIRD-HAND TOBACCO SMOKE: SIGNIFICANTVECTOR FOR PAH EXPOSURE OR NON-ISSUE?

Tyler Fleming, Chris Anderson, Sarang Amin, and Jeffrey Ashley*

Philadelphia University, Philadelphia, Pennsylvania, USA

*ashleyj@philau.edu

DOI:10.1002/ieam.1337

Everyone is familiar with the offensive smell that emanatesfrom smokers after they have taken a ‘‘cigarette break.’’ Thisgaseous and particulate residue adsorbed onto smokers’clothing and/or skin, as well as any other surfaces such aswalls, carpets, and furniture of indoors environments, has

been coined ‘‘third-hand smoke’’ (Winickoff et al. 2009). Ithas been demonized in the popular press, which describe it asa ‘‘toxic stew’’ of chemicals capable of eliciting a host ofpotential health problems, particularly for infants andchildren. However, scientific studies supporting this positionare sparse, and even fewer studies evaluate exposure risks andpotential deleterious health implications of third-handtobacco smoke residues on surfaces such as walls, carpets,and furniture of indoor environments.

Studies over the past 2 decades have concluded thatpolycyclic aromatic hydrocarbons (PAHs), a suite of chem-icals produced from the incomplete combustion of carbon-containing materials, are present in mainstream and side-stream smoke at concentrations as high as 0.1 to 0.25 ng/cigarette (Menzie et al. 1992). Toughening indoor smokinglaws has undoubtedly led to reductions in exposure of theseand other chemicals to nonsmokers. However, Matt et al.(2004) concluded that limiting smoking to the outdoorscontaminated indoor settings 5 to 7 times more than notsmoking at all. Third-hand smoke may represent a significantvector for carcinogen exposure, especially to high-riskindividuals such as infants who ingest 0.05 to 0.25 g of dustper day, including any PAHs that have adsorbed onto carpetor clothing material (Matt et al. 2004), or may come intocontact with a smoker’s skin.

To date, most of the limited research regarding third-handsmoke has focused on either using nicotine as an indicator forthird-hand residue, or it has investigated nicotine’s hypothe-sized role as a precursor in the formation of carcinogeniccompounds within indoor environments (Sleiman et al.2010). The myriad of other potential health hazardouscompounds within third-hand smoke, including PAHs, havelargely been ignored, and it was our intention to go beyondthe studies that focused on nicotine contamination andevaluate PAH residues in third-hand smoke.

Because there are few published values for PAH concen-trations in third-hand tobacco residues, we conducted apreliminary study quantifying PAH concentrations in third-hand smoke residues remaining on smokers’ hands. We used‘‘swipes’’ of hands, an increasingly popular and simplemethod for collecting adsorbed compounds from surfaces.Alcohol-soaked cotton ball swipes from the hands of 170smokers (after smoking 1 cigarette) and 160 nonsmokers wereanalyzed. Individual swipes of treatment and control groupswere composited to 8 to 10 swipes (to constitute a ‘‘sample’’)to increase instrumental detection limits.

Composited swipe samples were extracted with hexaneusing a Soxhlet extractor for 18 h and ‘‘cleaned-up’’ usingbench-top solid-liquid chromatography with alumina as thestationary phase and hexane as the mobile phase. Sampleswere subsequently concentrated under N gas and a perdeu-terated PAH (fluoranthene-d10) was added as the internalstandard. Twenty individual PAHs were quantified by gaschromatography mass spectrometry using a 5-point calibra-tion curve. Mean recoveries of a perdeuterated PAH(perylene-d12) surrogate were 67%.

Given the ubiquitous nature of PAHs in the environment,it was not surprising that all PAH compounds were detectedabove blank-based detection limits from swipes collectedfrom both the smokers’ and nonsmokers’ hands. However,concentrations (expressed as the sum of all PAH compoundsper swiped hand) were significantly higher (confidenceinterval at 90% for 17 of 20 PAHs) for hands directly exposed

764 Integr Environ Assess Manag 8, 2012—PM Chapman, Editor

to tobacco smoke versus nonsmokers’ hands (34 ng/hand vs13 ng/hand, respectively). From this preliminary study, weconclude smoking cigarettes significantly increases PAHresidue on smokers’ hands by approximately 3 times that ofnonsmokers.

This study attempted to be as realistic as possible whenevaluating third-hand PAH residues resulting from 1 ciga-rette. Smokers were not asked to change their smoking habits,except to continuously hold the cigarette in 1 hand duringthe entire duration of the cigarette’s burning. Hand size (thatis, the adsorptive surface area), duration of smoking, andenvironmental conditions such as wind, temperature, andhumidity, in addition to other factors, may potentiallyinfluence PAH concentration. We conducted our third-handsmoke studies outdoors under environmental conditions, andtherefore hypothesize that a similar study conducted in themore stable conditions of an indoor environment may revealhigher levels of contaminant residues on surfaces andsmokers’ bodies.

Moir et al. (2008) quantified PAH concentrations insecond-hand tobacco smoke, defined as environmentaltobacco smoke that is inhaled involuntarily or passively bysomeone who is not smoking. Using their study and our dataset, we carried out a ‘‘back of the envelope’’ calculation toestimate the percentage of sidestream smoke (i.e., second-hand smoke) that becomes third-hand smoke. We concludethat the PAH inventory on 1 hand of a smoker represents0.1% to 6% of that emitted from sidestream smoke.

Third-hand PAH residues on a smoker’s hand representonly a fraction of the total PAH reservoir for a smoker(compared to residues on all exposed skin and clothing). Wehave begun to quantify this load of chemicals as the first stepin assessing the potential for smokers to act as vectors forimpairment of indoor air quality. To completely capture thehealth risk posed by third-hand smoke, further studies fromour research group and others need to address the off-gassingor desorption potential of these compounds and more fullyevaluate the significance of third-hand smoke residues inimpairing indoor air quality and/or increasing PAH exposureto subpopulations such as children. A thorough ranking ofthe importance of this exposure route compared to otherexposures modes (e.g., release of PAHs from cookingmethods such as open fires, incense burning, indoor tobaccosmoking, etc.) also remain to be quantified.

REFERENCESMatt G, Quintana P, Larson S, Hovell M, Bernert J, Song S, Novianti N, Juarez T, Floro

J, Gehrman C., et al. 2004. Households contaminated by environmental

tobacco smoke: Sources of infant exposure. Tobacco Control 13:29–37.

Menzie C, Potocki B, Santodonato J. 1992. Exposure to carcinogenic PAHs in the

environment. Environ Sci Technol 26:1278–1282.

Moir D, Rickert W, Levasseur G, Larose Y, Maertens R, White P, Desjardins S. 2008.

A comparison of mainstream and sidestream marijuana and tobacco cigarette

smoke produced under two machine smoking conditions. Chem Res Toxicol

21:494–502.

SleimanM, Gundel L, Pankow J, Jacob P, Singer B, Destaillats H. 2010. Formation of

carcinogens indoors by surface-mediated reactions of nicotine with nitrous

acid, leading to potential thirdhand smoke hazards. PNAS 107:6576–6581.

Winickoff J, Friebely J, Tanski S, Sherrod G, Matt G, Hovell M, McMillen R. 2009.

Beliefs about the health effects of ‘‘Thirdhand’’ smoke and home smoking

bans. Pediatrics 123:74–79.

WHAT TO DO WITH NOECS/NOELS—PROHIBITIONOR INNOVATION?

David R Fox,*y Elise Billoir,z Sandrine Charles,§

Marie Laure Delignette-Muller,§ and Christelle Lopes§

yEnvironmetrics Australia and University of Melbourne, Victoria,

Australia

zPlateforme de Recherche ROVALTAIN en Toxicologie

Environnementale et Ecotoxicologie, Valence, France

§Universite de Lyon, Lyon, France

*david.fox@environmetrics.net.au

DOI: 10.1002/ieam.1350

Now more than 30 years old, ecotoxicology’s ‘‘problemchild’’—the no observed effect concentration/no observableeffect level (NOEC/NOEL), continues to cause us grief.Recent articles by Landis and Chapman (2011), van Damet al. (2012), Fox (2012), and Jager (2011) have reiteratedlong-known concerns with NOECs and NOELs as toxicitymeasures, and each has adopted a particular view on how tobest move forward. Those views fall broadly into 2 camps:the prohibition camp that argues for a ban on the use andreporting of NOECs/NOELs, and the education camp thatargues for skills enhancement and tool development. Weplace ourselves firmly in the latter category. We understand athird group, the status quo camp, which argues for theretention of NOECs and NOELs (perhaps with addedcaveats) is soon to emerge. The purpose of this LearnedDiscourse is to provide a clearer articulation of ‘‘the problem’’as we see it and, importantly, to provide some constructivesuggestions for an orderly transition to model-based toxicityestimation.

In a nutshell, the NOEC/NOEL ‘‘controversy’’ stems frominappropriate use of hypothesis testing in general and multi-ple comparison techniques in particular. We are not the firstto raise this issue. For example, Newman and Clements(2008) note problems with the use of hypothesis testing toestimate toxicity measures and state ‘‘the virtues and short-comings of these 2 approaches have been and still aredebated. . .this debate extends back to the origins of theseapproaches.’’

So what does it take to effect change? Landis and Chapman(2011) argue that a ban is required. We agree that the timefor action is now, but we remain unconvinced thatprohibition will work or that it is even appropriate. Theremay be a few instances (such as a screening level riskassessment) where one simply wants to ascertain whetherthere is a toxic effect and hypothesis testing is an appropriateparadigm. Or, we might want to get a sense of theconcentration ‘‘neighborhood’’ where that toxic effect ‘‘kicksin’’ and use this to inform the design of a follow-upconcentration-response experiment—Dunnett’s test is anappropriate tool. What is not appropriate is the use ofhypothesis tests to generate point estimates of toxicity.

To be clear, statistical inference is concerned with 2related but distinct problems: 1) hypothesis testing, and 2)estimation—it is ‘‘the process of making conclusions on thebasis of data that are governed by probability laws’’ (Zelen2005). Our conceptual model for statistical inference(Figure 1) suggests that, in the context of ecotoxicology,hypothesis tests should be used to assess the presence of atoxic effect whereas estimation techniques should be usedto derive a measure of a toxic effect. If one accepts this