The Air API is available via XMLRPC at the moment with REST and JSON retrieval coming shortly. The Air API allows you not only to pull the data from this website but also to push data back to the website for independent air quality analysis.
Retrieve data
air.get($city, $type = PM10, $date = latest(), $dateto = NULL)
Pass a city name into this function and an array containing the latest data will be returning. You can get more specific data by passing in $type (must be in air.types). you can also get retrieve historical data and/or a date range by passing in a $date and a $dateto.
air.get_latest($city, $type = PM10)
This function is identical to air.get except that it returns a single array instead of a multiple array to make processing easier. It only return that last known number for a metric and only from the default source (China's MEP). You can get more specific data by passing in $type (S02, PM10, H02, etc.). Just
air.get_max($city, $type = PM10)
Returns the highest known number for the specified city and type (optional).
air.get_min($city, $type = PM10)
Returns the lowest known number for the specified city and type (optional).
air.get_avg($city, $type = PM10)
Returns the average number for the specified city and type (optional) according to all data points in the system
air.cities($type = all)
Returns a list of all cities available
air.types($city = all)
Returns a list of all available metrics for a given city
Save data
Have an air quality number that you would like to share? You'll need an account as well as an API key in order to push data to this site but once you have those items its very quick n' easy.