Preventive and Control Measures for the Coronavirus Pandemic in Clinical Dentistry.

A severe public health crisis has been declared worldwide since coronavirus disease 2019 (COVID-19) was classified as a pandemic of acute respiratory infectious disease by the World Health Organisation (WHO). China has taken strict measures to curb the spread of the disease to save lives, and has managed to control the outbreak. COVID-19 is mainly transmitted through respiratory droplets and close physical contact, so it is challenging to prevent nosocomial infection and possible spread during dental treatment.

[Observational Study of Air Pollution Complex in Nanjing in June 2014].

Studying the evolution of secondary inorganic aerosols, which are important components of PM, is crucial to improving our understanding about the air pollution in big cities. This study investigates the evolution and factors of secondary inorganic aerosols based on two pollution incidences in Nanjing in June 2014. A significant characteristic of air pollution complex with the coexistence of higher concentrations of both PM and ozone is observed.