Table 4.

Urinary levels of SPMAa in hookah smokers and non-smokers (≥18 years) pre and post hookah-only social events in hookah lounge versus home (N = 208)

Hookah loungeHome
Hookah-only social event (n = 108)Hookah-only social event (n = 100)
pmol/mLpmol/mL
Pre eventPost eventRatiobPcPre eventPost eventRatiobPdPePf
All hookah smokers (n = 105)
 M (±SD)g0.47 (±0.81)1.75 (±2.27)<0.0010.71 (±0.84)1.21 (±1.72)0.0300.0590.023
 GM (95% CI)h0.15 (0.09–0.24)0.69 (0.45–1.08)4.60.28 (0.18–0.45)0.51 (0.33–0.78)1.8
 Median (5–95 percentile)0.19 (0.02–2.04)1.11 (0.02–7.91)5.80.34 (0.02–2.25)0.58 (0.02–5.07)1.7
 (Minimum–maximum)(0.02–4.57)(0.02–10.60)(0.02–3.80)(0.02–8.44)
 % above LODi (Freq/n)j77% (41/53)94% (51/54)86% (43/50)94% (47/50)
Daily hookah smokers
 M (±SD)1.34 (±1.92)4.09 (±3.29)0.0431.11 (±1.03)2.01 (±2.41)0.0470.8960.032
 GM (95% CI)0.44 (0.05–4.28)2.93 (0.88–9.70)6.70.53 (0.21–1.34)1.21 (0.70–2.09)2.3
 Median (5–95 percentile)0.26 (0.04–4.57)3.09 (1.02–7.91)11.90.89 (0.02–3.80)1.06 (0.32–8.44)1.2
 (Minimum–maximum)(0.04–4.57)(1.02–7.91)(0.02–3.80)(0.32–8.44)
 % above LOD (Freq/n)100% (5/5)100% (5/5)87% (13/15)100% (15/15)
Weekly hookah smokers
 M (±SD)0.33 (±0.57)1.86 (±2.78)0.0020.40 (±0.50)1.07 (±1.34)0.0190.1410.150
 GM (95% CI)0.08 (0.03–0.18)0.67 (0.31–1.44)8.40.17 (0.09–0.31)0.44 (0.23–0.84)2.6
 Median (5–95 percentile)0.07 (0.02–1.84)0.82 (0.06–9.36)11.70.19 (0.02–1.29)0.53 (0.02–4.04)2.8
 (Minimum–maximum)(0.02–2.04)(0.02–10.60)(0.02–2.05)(0.02–4.82)
 % above LOD (Freq/n)55% (11/20)95% (19/20)81% (21/26)92% (24/26)
Occasional hookah smokers
 M (±SD)0.46 (±0.58)1.27 (±1.32)0.0030.96 (±0.97)0.29 (±0.28)0.1390.1280.011
 GM (95% CI)0.20 (0.11–0.36)0.55 (0.30–1.03)2.80.44 (0.14–1.39)0.18 (0.07–0.44)0.4
 Median (5–95 percentile)0.30 (0.02–1.09)1.05 (0.02–3.56)3.50.68 (0.08–2.38)0.21 (0.02–0.92)0.3
 (Minimum–maximum)(0.02–2.86)(0.02–5.28)(0.08–2.38)(0.02–0.92)
 % above LOD (Freq/n)89% (25/28)93% (27/29)100% (9/9)89% (8/9)
Non-smokers (n = 103)
 M (±SD)0.22 (±0.65)0.36 (±0.79)0.0620.43 (±0.82)0.33 (±0.58)0.2850.0400.059
 GM (95% CI)0.05 (0.03–0.08)0.10 (0.07–0.16)2.00.10 (0.06–0.17)0.10 (0.06–0.15)1.0
 Median (5–95 percentile)0.02 (0.02–0.93)0.13 (0.02–1.54)6.50.12 (0.02–2.19)0.12 (0.02–1.60)1.0
 (Minimum–maximum)(0.02–4.50)(0.02–4.78)(0.02–4.37)(0.02–2.90)
 % above LOD (Freq/n)46% (24/52)56% (29/52)59% (29/49)64% (32/50)
PkPkPLPkPkPL
 Daily vs. weekly0.0820.1030.1350.0170.0510.787
 Daily vs. occasional0.4510.0390.0270.743<0.0010.022
 Daily vs. non-smoker0.012<0.0010.0010.003<0.0010.011
 Weekly vs. occasional0.0650.7450.1490.1860.0890.010
 Weekly vs. non-smoker0.346<0.0010.0020.297<0.0010.007
 Occasional vs. non-smoker<0.001<0.0010.0250.0290.2470.209
  • aSPMA = S-Phenylmercapturic acid, a metabolite of benzene, in pmol/mL.

  • bRatio = ratio of post to pre hookah event SPMA GMs and medians.

  • cP Hookah lounge: pre vs. post event; P Home: pre vs. post event.

  • c,dP values were derived from Wilcoxon signed-rank tests; two-tailed α level P < 0.05.

  • eP pre event: hookah lounge vs. home.

  • fP change in SPMA hookah lounge vs. home.

    e,f,k,LP values were derived from Mann–Whitney U tests; two-tailed α level P < 0.05.

  • gM (±SD) = arithmetic mean and SD.

  • hGM (95% CI) = geometric mean and 95% confidence interval. All SPMA values and percentages are rounded up.

  • i% above LOD = percentage of urine samples above the limit of detection: SPMA LOD = 0.03 pmol/mL.

  • jFreq/n = frequency of samples with levels above the LOD/n size of samples per group; nondetectable values of SPMA were replaced with (LOD/2 = 0.015 pmol/mL).

  • kP SPMA levels by smoking frequency status.

  • LP pre to post event change in SPMA levels by smoking frequency status; P significant levels are shown in bold.