Comparison of NO2 and SO2 Measurements Using Different Passive Samplers in Tropical Environment

Abstract

This report describes the results of an inter-comparison study conducted for the sampling and analysis of NO 2 and SO 2 by using different type of passive samplers in tropical urban environment. For this purpose, field experiments were proposed to be conducted by two round robin tests from Sept. 2007 to Aug. 2008 in Singapore. A set of different types of passive samplers have been exposed to ambient air at atmospheric research station in National University of Singapore along with suitable active samplers (as reference method) for a sufficient period of time (3-4 weeks). Annular denuder system (ADS) active sampling data showed that NO 2 concentration level (23.8-28.1 ppb) in Singapore was slightly higher than the WHO guideline but SO 2 concentration (12.5-14.9 ppb) was approximately twice the value of WHO guideline. For the two round robin tests, accuracy analysis by using active sampling data as reference demonstrated that grand mean values from passive air sampling (PAS) and active sampler average concentrations, for both NO 2 and SO 2 , are in close agreement with each other. Precision evaluation based on the triplicate samplers co-located at the same sampling siteSingapore showed that most of the passive samplers applied here had repeatability. ANOVA statistical analysis also showed no significant difference between the measurement data obtained by different type of passive samplers for both round robin tests in Singapore.

Spatial distribution of gaseous pollutants (NO<sub>2</sub>, SO<sub>2</sub>, NH<sub>3</sub>, HNO<sub>3</sub> and O<sub>3</sub>) in Abidjan, Cote d'Ivoire

“…In Abidjan, we can assume that the risk exist because of the location of the industrial areas near some important residential places. Mean NO2 concentration measured at the industrial sites of Abidjan (20.9 ppb) is of the same order of magnitude than concentrations measured at the urban site of Singapore (23.8-28.1 ppb) in South East Asia reported by (He et al, 2014). It remains lower than that obtained at the traffic sites of Dakar (31.7 ppb) and Al Ain city in the Middle East (31.5 ppb) (Adon et al (2016) and Salem et al 10 (2009)).…”

Passive Sampling as a Low-Cost Method for Monitoring Air Pollutants in the Baikal Region (Eastern Siberia)

“…Researchers in many countries have conducted long-term measurements of nitrogen and sulfur oxides [41][42][43]. In particular, the passive sampling method allows the state of the atmosphere in mountainous and forested areas, rural settlements and other places, to be assessed [44,45].…”

Distribución Espacial De Concentraciones De So2, Nox Y O3 en El Aire Ambiente De Manizales

“…La diferencia entre ambas técnicas representa un sesgo relativo del 76 % (tomando como concentración de referencia la medida por monitoreo automático). Aunque múltiples estudios registran sesgos aceptables < 25 % al comparar mediciones por métodos pasivos y activos (Ferm y Svanberg 1998, Cruz et al 2004, He et al 2014, el sesgo del 76 % calculado en P7 se asocia con la variabilidad de concentraciones de SO 2 registradas a lo largo del día por el analizador automático como picos de concentración producto de…”

“…La concentración promedio de O 3 medida de forma automática fue de 28.4 µg/m 3 (± 11.6 µg/m 3 ), en tanto que la concentración medida por monitoreo pasivo fue de 21.7 µg/m 3 . La diferencia entre ambas técnicas representa un sesgo relativo del 24 %, aceptable según varios estudios donde se comparan técnicas automáticas y pasivas (Ferm y Svanberg 1998, Cruz et al 2004, He et al 2014). Las concentraciones de O 3 medidas por monitoreo automático durante la campaña 1 variaron a lo largo del día entre 0.006 y 80 µg/m 3 .…”