The Holiday Effect - Chinese New Year

Gong Xi Fa Cai! This year, the start of February marks the first day of the Chinese New Year. Although the number of COVID-19 Omnicron cases have been steadily rising, it has not dampened Singaporeans' festive spirits, and many are going ahead with their plans for the celebrations. Understandably so, as the holiday during the mid-week allows for much rest and recuperation. However, what does Chinese New Year mean for the environment?  The 'Holiday Effect', a term coined by Tan et al., (2009), describes the difference in air pollutant concentrations between holiday and non-holiday periods. In their paper, the authors assess the hourly and daily measurements of six major forms of air pollution - Nitrogen Oxides (NOx), Carbon Monoxide (CO), Non-methane Hydrocarbon (NMHC), Ozone (O3), Sulfur Dioxide (SO2), and PM10 particles - from 1994 to 2006, during CNY periods and non-Chinese New Year (NCNY) periods, which are defined as 10 days before after the actual celebration dates. The results were as observed below: 

In this paper, the main focus was on traffic and exhaust from vehicles being the main source of NOx, CO and NMHC emissions. In general, there are higher concentrations of atmospheric pollutants during the weekdays as compared to the weekends due to commuting activities. Similarly, particulate matter concentrations, which are found to be higher in indoor environments such as office buildings and schools, were also observed to be higher on weekdays. For their study during the CNY and NCNY period in Taipei, there was the assumption that right before and after the celebrations, people would travel long distances to family homes for reunions resulting in an increase in vehicular emissions. The results above show that NOx, CO, NMHC, SO2 and PM10 were lower on CNY than NCNY period, indicating an improvement in air quality. Although this is seemingly positive and beneficial for the environment, it is worth noting that the NCNY periods also spiked local emissions due to the aforementioned activities of travelling.  

The Taipei Metropolitan area is a densely-populated one, similar to Singapore. This makes it a relevant and applicable study that can be used to analyse the conditions during CNY in Singapore. However, there is also the obvious fact that COVID-19 has restricted travelling. Travel has become somewhat a risk, thus some people may be prevented or deterred from visiting their relatives. Furthermore, the limitations imposed on social gathering sizes can also affect patterns of travel, making it difficult to predict this year's air pollution trends. Whatever the case, the 'Holiday Effect' is certainly an interesting one that can be applied to other public/ national holidays as well.  

References: 

Tan, P.-H., Chou, C., Liang, J.-Y., Chou, C. C.-K., & Shiu, C.-J. (2009). Air pollution “holiday effect” resulting from the Chinese New Year. Atmospheric Environment, 43(13), 2114–2124. https://doi.org/https://doi.org/10.1016/j.atmosenv.2009.01.037