Microplastics in atmospheric dust samples of Sistan: sources and distribution.

In this work, the amount and physical and chemical characteristics of airborne microplastics (MPs) pollution in dust samples in Sistan, located in the eastern part of Iran, is reported. Sampling stations were selected according to the wind direction and population density. MPs were collected by a static dust sampler and analyzed by optical microscopy and FT-IR spectroscopy. Results showed that the distribution frequency of MPs in residential and non-residential areas was 6 to 11 pieces per 100 g (pcs/100 g) with an average abundance of 9.8 pcs/100 g. Fragmented MPs were approximately consisted 64% of total MPs and their sizes were in the range of 0.9-3.8 mm. Polyethylene (49%), polystyrene (21%) and polyester (18%) were the main MPs presented in the dust samples. It was observed that population density and wind direction were the most important parameters affecting MPs pollution in dust. Supplementary Information: The online version contains supplementary material available at 10.1007/s40201-022-00833-y.

Air Surveillance for Viral Contamination with SARS-CoV-2 RNA at a Healthcare Facility.

The transmission pathway of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 also called COVID-19 disease) in indoor environments are the main area of contention between health systems and scientists. In this context, little has been investigated about the collection of airborne viral shedding. Here, we collected air samples from 24 locations inside the sole COVID-19 patient care center in Zabol, Iran, for screening SARS-CoV-2 RNA from March to May 2021. Locations included the ICU, COVID-19 wards (CWs) rooms, corridors, nearby nurses' stations, and toilets. We identified the SARS-CoV-2 RNA in breathing zone of CW, in room air, with the positivity rate of 2.5% at a concentration of 17 × 103 virus genome copies/m3 air. It also investigates the relationship between local climate conditions [i.e., temperature and relative humidity] and COVID-19 transmission with the evolution of daily official data on the number of new cases, hospitalizations, and deaths. Current data explained that the difference of temperature and humidity may affect the behavior of virus along with other factors, i.e., population density, individual viral shedding, and infectious dose of SARS-CoV-2 (both indoor and outdoor). Our data support the potential SARS-CoV-2 airborne transmission indoors suggesting the specific safety assessment of building to improve ventilation solutions besides proper using face masks and extensive public health interventions.

Determination of carbamazepine in urine and water samples using amino-functionalized metal-organic framework as sorbent.

A stable and porous amino-functionalized zirconium-based metal organic framework (Zr-MOF-NH2) containing missing linker defects was prepared and fully characterized by FTIR, scanning electron microscopy, powder X-ray diffraction, and BET surface area measurement. The Zr-MOF-NH2 was then applied as an adsorbent in pipette-tip solid phase extraction (PT-SPE) of carbamazepine. Important parameters affecting extraction efficiency such as pH, sample volume, type and volume of eluent, amount of adsorbent, and number of aspirating/dispensing cycles for sample solution and eluent solvent were investigated and optimized. The best extraction efficiency was obtained when pH of 100 µL of sample solution was adjusted to 7.5 and 5 mg of the sorbent was used. Eluent solvent was 10 µL methanol. Linear dynamic range was found to be between 0.1 and 50 µg L-1 and limit of detection for 10 measurement of blank solution was 0.05 µg L-1. This extraction method was coupled to HPLC and was successfully employed for the determination of carbamazepine in urine and water samples. The strategy combined the advantages of fast and easy operation of PT-SPE with robustness and large adsorption capacity of Zr-MOF-NH2.