(CNN) -- Beijing residents blanketed by smog are pointing to U.S. readings on pollution levels -- and slamming official reports from the Chinese government.
On Weibo, the Chinese version of Twitter, more and more people are uploading and reposting screen captures from air-quality-monitoring apps -- generally one from the U.S. Embassy -- highlighting "very unhealthy" or "hazardous" pollution levels, at times that China officially reported only "slight pollution" in the same areas.
China acknowledges the concerns and notes that it uses a different system to measure air pollution.
State-run news agency Global Times on Tuesday carried the headline, "Non-government air quality assessments on the rise due to distrust over official data."
"Zeal for independent assessments of air quality has been on the rise nationwide in China recently, amid public distrust over official data resulting from the failure of national evaluations to include PM 2.5 level, an air pollution index used worldwide, in their calculations," the article states.
The U.S. Embassy explains that PM 2.5 refers to fine particulates less than 2.5 micrometers in diameter.
The U.S. Consulate General in Guangzhou, China, explains that these smaller particles "are believed to pose the largest health risks" and "are small enough to get into the lungs and even the blood stream."
Chinese monitoring stations around Beijing track only larger, "coarse" particulates, between 2.5 and 10 micrometers in diameter.
On Monday, the Beijing Municipal Environmental Protection Bureau stated that the Air Pollution Index (API) was between 150 to 170, indicating "slight" pollution.
The U.S. monitor, meanwhile, which sends out tweets throughout the day, reported at times on Monday that the air in Beijing was "hazardous," with Air Quality Index (AQI) readings over 300.
On October 9, the U.S. monitor reported a reading of over 500, which it labeled "beyond index." The official government reading for that same date states there was "slight pollution."
While many official reports on Chinese state-run media refer to the air as being filled with "fog," the government acknowledges the haze is due to smog.
The state-run China Daily reported this week that while "fog alerts" are declared, "Ma Jun, director of the Institute of Public and Environment Affairs, said the hazes that have been smothering Beijing are really 'smog.'"
While pollution is an ongoing concern in the country, the weather in recent days has made matters worse, said CNN International weather anchor Mari Ramos.
"Beijing's weather has been dominated by high pressure, which means sinking air and dry days. This weather pattern aggravates their air quality problem," Ramos said.
"The air is stagnant, there is no mixing and all the pollutants are trapped near the surface."
The Chinese capital has only had 1.5 mm of rain since October 14, she said.
"There is a glimmer of hope on the horizon, but not until the end of the week. By Friday, when a cold front comes through, there is a small chance of rain," Ramos said, adding that even if it doesn't rain, the end to the current weather pattern will bring a "welcome relief."
In posts online, many Chinese people say they can smell sulfur dioxide in the air.
Some have posted photos of sites throughout Beijing, showing how little visibility there is.
The poor air quality has caused a surge in the numbers of patients with respiratory problems, and the Beijing Meteorological Bureau issued four yellow alerts for dense fog in the last two days, the Global Times article says. Doctors suggest people of all ages avoid outdoor activities.
CNN's Tian Shao and Jaime FlorCruz in Beijing contributed to this report.