One of China’s gravest public concerns is its rampant air pollution, covering the country’s big cities with toxic air. In addition to being a serious health threat, China’s seemingly impenetrable smog is also proving to be a bit of a national security issue.

A few weeks ago, the northeastern city of Harbin, the capital of Heilongjiang province, was hit with a bout of one of the city’s worst cases of pollution. The smog was so thick that visibility reportedly dropped to just three meters (nine feet). According to various scientists and engineers quoted in the South China Morning Post, on bad smog days, surveillance cameras around the city aren’t able to see through the air.

It seems that China’s biggest threat to national security and its Big Brother-style surveillance is itself. The central government’s sprawling network of surveillance cameras, which keeps eyes on every major street in every major city, essentially is blinded on bad pollution days -- days that are becoming increasingly common.

As a result, some are starting to worry that criminals could pick one of the many smoggy days to pounce, and crime could surge. Those concerns have prompted some surveillance technology experts to begin developing more advanced cameras that can see clearly, even on the worst pollution days. Kong Zilong, a senior project engineer with Shenzhen Yichengan Technology and an expert in video surveillance, says such cameras are yet to be invented, but that doesn’t mean people aren’t already trying. The National Natural Science Foundation of China is funding two programs, one for civilian use and one for military use, that will study the issue with the goal of developing a solution within four years.

Yang Aiping, a professor and expert in digital imaging with the School of Electronic Information Engineering at Tianjin University, is leading the civilian technology team. She says her project has experienced a lot of hiccups along its development because pre-existing data does not deal with pollution directly. “Most studies in other countries are to do with fog,” she said. “In China, most people think that fog and smog can be dealt by the same method. Our preliminary research shows that the smog particles are quite different from the small water droplets in terms of optical properties.”

While the problem facing their research has been determined, Yang says there’s still a long way to go before finding a solution. “We need to heavily revise, if not completely rewrite, algorithms in some mathematical models. We also need to do lots of computer simulation and extensive field tests.”

One solution to the visibility problem, proposed by Professor Zhang Li, an image processing expert at Beijing’s Tsinghua University, will just invite another health problem. Radar technology would use microwaves or electromagnetic waves, able to easily travel through smog and bounce back after hitting an object. Working with good imaging software, sharp, clear images would be produced. Zhang warns, however that such technology would have to be a “contingency device” because the radiation generated by the cameras is potentially harmful to health.