The occurrence of emerging compounds in real urban wastewater before and after the COVID-19 pandemic in Cali, Colombia.

The COVID-19 pandemic is considered one of the most significant global disasters in the last years. The rapid increase in infections, deaths, treatment, and the vaccination process has resulted in the excessive use of pharmaceuticals that have entered the environment as micropollutants. Considering the prior information about the presence of pharmaceuticals found in the wastewater of Cali, Colombia, which was collected from 2015 to 2022. The data monitored after the COVID-19 pandemic showed an increase in the concentration of analgesics and anti-inflammatory drugs of up to 91%. This increase was associated with the consumption of pharmaceuticals for mild symptoms, such as fever and pain. Moreover, the increase in concentration of pharmaceuticals poses a highly ecological threat, which was up to 14 times higher than that reported before of COVID-19 pandemic. These results showed that the COVID-19 had not only impacted human health but also had an effect on environmental health.

Potentially toxic elements (PTEs) in Gomti-Ganga Alluvial Plain, associated human health risks assessment and potential remediation using novel-nanomaterials.

The health risks associated with consumption of water from river Gomti polluted with potentially toxic elements (PTEs), including As, Fe, Pb, Cd, Mn, Cr, Ni, and Hg were investigated at the initiation of unlocking of COVID-19 lockdown and compared with pre-COVID-19 lockdown status. In the current investigation, the total hazard index (THI) values exceeded the acceptable limit of "unity" at all sampling stations. The use of river water for drinking and domestic purposes by millions of people with high THI values has emerged as a matter of huge concern. The individual hazard quotients associated with Cd and Pb were found to be most severe (> 1). A vivid difference between the THI values during the two study phases indicated the positive impact of COVID-19 lockdown signifying the prominent impact of anthropogenic activities on the PTE concentrations. The closure of local manufacturing units (textile, battery, etc.) emerged as a potential reason for decreased health risks associated with PTE levels. The higher susceptibility of children to health risks in comparison with adults through the values of THI and HQs was interpreted across the study area. Potential remedial measures for PTE contamination have also been suggested in the study.

Particulate matter concentration and health risk assessment for a residential building during COVID-19 pandemic in Abha, Saudi Arabia.

Building and its environment are in focus owing to health impact attributed to indoor air quality. This study was carried out to assess indoor air quality in terms of particulate matter (PM) and carbon dioxide in a residential building, during COVD-19 pandemic lockdown from March 25 to April 23, 2020, Abha, Saudi Arabia. The PM concentration range for kitchen, bedroom, and hall were 40,000-81000 µg/m3 (PM0.3), 15,000-26000 µg/m3 (PM0.5), 4000-6000 µg/m3 (PM1), 1100-1500 µg/m3 (PM2.5), 160-247 µg/m3 (PM5), and 60-95 µg/m3 (PM10). The results of this study suggest that bedroom needs to be ventilated as CO2 concentration was reaching 700 ppm during sleep hours. PM concentration was exceeding 300 µg/m3 (unhealthy) for all particle sizes of PM0.3, PM0.5, PM1, and PM2.5 except for PM10 which was also above safe limits (0-50 µg/m3). Also, with influential habit (aromatic smoke), these concentrations increased 2-28 times for PM. The hazard quotient value greater than 1 revealed potential health risk to the inhabitants. Hence, future studies are needed for developing indoor air quality guidelines for residential buildings in Saudi Arabia and better planning and management of energy consumption.

Increased disinfection byproducts in the air resulting from intensified disinfection during the COVID-19 pandemic.

Intensified use of disinfectants to control COVID-19 could unintentionally increase the disinfection byproducts (DBPs) in the environment. In indoor spaces, it is critical to determine the optimal disinfection practice to prevent the spread of the virus while keeping DBPs at relatively low levels in the air. The formation of DBPs exceed 0.1 µg/mg while hypochlorite dosed at >10 mg/m3. The total DBP concentrations in highly disinfected places (100-200 mg/m3 hypochlorite) were as high as 66.8 µg/m3, and the Hazard Index (HI) was up to 0.84, and both values were much higher than those in less disinfected places (<10 mg/m3 hypochlorite). Taking into account the HI, formation yields and the origin of the DBPs, we recommended 10 mg/m3 as the suggested hypochlorite dose to minimize DBPs generation during routine disinfection for controlling the coronavirus. DBPs in indoor air could be eliminated by ventilation, reducing the usage of personal care products, and wiping the solid surface with water before or after disinfection. These results highlighted the necessity to control air-borne DBPs and their associated health risks arising from intensified disinfection, and will guide the further development of evidence-based regulation on DBP exposure during disinfection and improve public health protection.

Particulate matter concentrations and their association with COVID-19-related mortality in Mexico during June 2020 Saharan dust event.

The present study evaluated the impact of Saharan dust event on particulate matter (PM: PM10 and PM2.5) concentrations by analyzing the daily average PM data between Saharan dust days (June 23-29, 2020) and non-Saharan dust days (June 15 to June 22 and June 30 to July 12, 2020) for four majorly affected regions in Mexico and by comparing with three major previous events (2015, 2018, and 2019). The results showed that PM10 and PM2.5 concentrations were 2-5 times higher during the Saharan dust event with the highest daily averages of 197 µg/m3 and 94 µg/m3, respectively, and exceeded the Mexican standard norm (NOM-020-SSA1-2014). When comparing with the previous Saharan dust episodes of 2015, 2018, and 2019, the levels of PM10 and PM2.5 considerably increased and more than doubled across Mexico. The correlation analysis revealed a positive association of PM levels with the number of daily COVID-19 cases and deaths during Saharan dust event. Furthermore, the human health risk assessment showed that the chronic daily intake and hazard quotient values incremented during Saharan dust days compared to non-Saharan days, indicating potential health effects and importance of taking necessary measures to ensure better air quality following the COVID-19 pandemic.