Troposheric ozone trend in the Muda irrigation area, Kedah

The ozone trend in the Muda Irrigation Area (MADA), Kedah, Malaysia, was assessed from the ozone data recorded in Su ngai Petani. Three parameters were selected as the robust trend indicators in the study: the monthly mean, the monthly averaged daily 1-h maximum and the number of annual hours > 120 g/m3. As the ozone data displayed obvious seasonal variation, using deseasonalised monthly average parameters to estimate the ozone trends could smooth out the influence of seasonal fluctuations. In this study, we used the Box-Jenkins methodology to build the Auto-Regressive Integrated Moving Average (ARIMA) model for the monthly ozone data taken from an Automatic Air Quality Monitoring System in Sungai Petani station for the period between 1999 and 2007, with a total 108 readings. The parametric, seasonally adjusted ARIMA (1, 0, 1) x (2, 1, 2) 12 model was successfully applied to predict the long-term trend of ozone concentration. The detection of a steady, statistically significant upward trend of ozone concentration in the area is a concern for human health and agricultural activities

Measuring secondhand smoke in homes in Malaysia: A feasibility study comparing indoor fine particulate (PM2.5) concentrations following an educational feedback intervention to create smoke-free homes during the COVID-19 pandemic

Introduction Extensive regulations have been introduced to reduce secondhand smoke (SHS) exposure among non-smokers in Malaysia. However, there is still a need to encourage behavior change of smokers in relation to making homes smokefree. This feasibility study aimed to use low-cost air pollution monitors to quantify SHS concentrations in Malaysian households and to explore the practicality of using personalized feedback in educating families to make their homes smoke-free. Methods A total of 35 smokers in three states in Malaysia were recruited via snowball and convenience sampling methods. Indoor fine particulate (PM 2.5 ) concentrations in participants’ homes were measured for 7 days before and after educational intervention using a pre-defined template, which included personalized airquality feedback, and information on SHS impacts were given. The feedback was delivered over two 20-minute phone calls or in-person sessions following the completion of the air-quality measurements. Data were corrected for outdoor PM 2.5 concentrations from the nearest environmental monitor. Results Despite the challenges in conducting the project during COVID-19 pandemic, the delivery of the intervention was found to be feasible. Twenty-seven (77%) out of 35 participants completed PM 2.5 measurements and received a complete intervention. The median (IQR: 25th –75th percentile concentrations) SHS-PM 2.5 concentrations at baseline and follow-up were 18.3 μg/m 3 (IQR: 13.3–28.3) and 16.2 μg/m 3 (IQR: 10.4 – 25.6), respectively. There was a reduction of SHS-PM 2.5 concentrations at follow-up measurement in the houses of 17 participants (63%). The change in corrected indoor PM 2.5 concentrations between baseline and followup was not statistically significant (Z= -1.01, p=0.29). Conclusions This educational intervention, combining the use of a low-cost air particle counter with personalized air-quality feedback, was found to be feasible in the Malaysian setting. It has potential to trigger behavior change among smokers, reducing indoor smoking and consequent SHS concentrations, and increasing smoke-free home implementation. A large-scale trial is needed