In the early morning, there was fog and dense fog in Nanjing, with visibility of 30 meters. The Municipal Meteorological Station issued red and orange warning signals of heavy fog respectively. Subsequently, with the help of sunshine, visibility gradually improved yesterday morning. However, due to the static and stable state of the atmosphere and poor air diffusion conditions, the visibility of the whole city was only about 5 km yesterday. Yesterday afternoon, Nanjing meteorological station issued a red warning signal of heavy fog. It is expected that in the next few days, dense fog or strong fog will appear in most areas of Nanjing, with visibility less than 50m in some areas.
According to the air quality forecast jointly issued by Nanjing Environmental Monitoring Center and Nanjing Meteorological Observatory, on November 27, Nanjing air quality was moderately to severely polluted, with an air quality index range of 195-215 and a pollutant of PM2.5; on November 28, Nanjing air quality was moderately to severely polluted, with an air quality index range of 195-215 and a primary pollutant of PM2.5. It is understood that 30 days ago, the city was still dominated by cloudy weather, with stable atmospheric stratification, small wind speed, high humidity, poor air dispersion conditions, and easy accumulation of pollutants. Nanjing will continue to maintain haze weather. From December 1 to 2, affected by cold air, the city's haze weather will decrease. According to the air quality status and weather forecast, considering the degree and duration of air pollution, the heavy air pollution is divided into four warning levels, which are in the order of four levels, three levels, two levels and one level, respectively marked by blue, yellow, orange and red. The first level (red) warning is the highest level.
PM2.5 refers to particles with a diameter of less than or equal to 2.5 microns in the atmosphere, also known as pulmonary particles. According to EPA air quality standards, outdoor physical activity should be avoided when PM2.5 concentration is between 250 and 500. At this time, it is a good choice to wear PM2.5 protective mask when going out.
One simple and effective way to travel in haze days is to wear masks. Now many people don't wear dust masks when they travel. This is a very incorrect thinking. There are many particles in haze days, which will bring great harm to health, so you must wear masks when you go out. 2. Drivers should pay attention to traffic safety. Driving precautions: low speed, driving lights on, turn on front and rear fog lights when serious, try not to open windows, etc. 3. Try to go to places with as few people as possible, with serious air pollution and relatively poor air flow, it is easy to cause the spread of respiratory diseases. 4. It's important to drink more water. Drinking more water can alleviate the harm of haze weather. In fact, it's the same as drinking more water for a cold.