A recent study conducted by California's Air Resources Board and South Coast Air Quality Management District collected particulate data from inside vehicles and obtained real-time information under a range of traffic and driving conditions. The study's objectives were to measure the personal exposure of drivers and passengers to common motor vehicle pollutants in Los Angeles and Sacramento, two areas known to have high levels of motor vehicle-generated air pollution. The study found that the air people breathe inside a car is 2 to 10 times more polluted than the air outdoors. Pollution levels of several dangerous contaminants are at least twice as bad inside as outside a vehicle, and the levels of other contaminants are as much as 10 times worse. Another in-vehicle health threat comes from the air conditioner, which contain bacteria and fungi that can trigger headaches, nausea, allergies, and asthma attacks. The only effective way to prevent law enforcement personnel from being exposed to in-vehicle air pollution and potentially life-threatening passenger contamination is by installing a vehicle quality air-purification unit. To be effective, an air purification system must operate separately from the vehicle's air conditioning unit and must have a long-lasting filter; reduce hazardous gases, odors, irritants, pollen, road pitch, microscopic tire dust, and passenger contamination; and have the ability to capture tuberculosis bacteria. Airsopure, a subsidiary of Airtech International Corporation, offers an air purification system for vehicles called the S-999. This unit captures up to 99.97 percent of all contaminants.