Spatial characteristics of urinary BTEX concentrations in the general population

Benzene, toluene, ethylbenzene, o-, m-, and p-xylenes (BTEX) are ubiquitous outdoor and indoor air pollutants associated with both environmental and health effects. The objective of this exploratory study was to determine the magnitude and variability of urinary BTEX levels among residents of two areas located in the same city (Nicosia, Cyprus). The two areas differed with respect to their proximity to an industrial cluster and an intercity-highway. First morning urine voids were collected during a random campaign from selected households in the two urban areas (n = 48). Urinary BTEX measurements were obtained using headspace solid phase micro extraction coupled with gas chromatography-mass spectrometry. The majority of participants were females (65%) and non-smokers (85%) with a mean age of 49 years. Median urinary BTEX levels were: 118 ng L^-1, 124 ng L^-1, 9 ng L^-1, 29 ng L^-1 and 28 ng L^-1 for benzene, toluene, ethylbenzene, (p + m)-xylene and o-xylene, respectively. With the exception of benzene, participants from area 2 (closer to the industrial cluster and an intercity road than area 1) had significantly (p < 0.05) higher urinary BTEX levels than those from area 1 (regression analysis). The residence location (in area 2) was the sole significant (p < 0.05) predictor of urinary BTEX levels after adjusting for sex, smoking, age, body mass index, and educational level. This observational study showed differences in BTEX exposures between two urban areas of the same city. This baseline BTEX dataset may prove useful for future activities of natural gas extraction and handling nearby urban settings.