How bad is the pollution in your Shanghai apartment?

Louie Cheng is the man -- the Shanghai apartment man.

Formerly the manager of his U.S. military unit’s nuclear, biological and chemical weapons program, today Cheng brings that same level of diligence to rooting out causes of pollution in Shanghai homes.

Last year Cheng co-founded home-testing company PureLiving China, and these days he and his technicians typically make several visits each week to client homes in Shanghai to test for contaminants including carbon monoxide, radon and lead.

The number one thing that people do wrong is buying solutions without knowing what is wrong with their air. You wouldn't go buy drugs without knowing what you are sick with.— Louie Cheng, founder of PureLiving

PureLiving China isn’t the only company in Shanghai that will test your home for these and other chemicals, but it is the only one that will give you something beyond meter-readings: probable causes and solutions to keep your home clean and safe.

Cheng calls getting your home tested, a “no-brainer,” especially if you have young children whose growing lungs are more sensitive to contaminants, not to mention all that time they spend crawling around on the floor huffing fumes.

In each case, Cheng first consults with the client to identify factors to investigate. On the day of the visit, that military diligence comes through in spades: Cheng checks the surrounding area for potential sources of pollutants (golf courses, for example, are hotbeds of pesticides and other chemicals), checks for mold behind bookshelves, gets down on his hands and knees to examine water valves, and takes two to three sample readings at each point for every test he conducts.

Once the results come back from the lab, Cheng breaks them down for his clients, does his own detective work to identify the causes of any particularly high readings, and recommends what residents can do to reduce the levels of pollutants in their homes.

• More on CNNGo: What are you breathing in Shanghai's bars and clubs?

Here are five Shanghai homes with common containment problems along with Cheng’s suggested fixes.

Shanghai apartment no. 1

A typical, slightly older downtown apartment complex, with lots of units pressed into a small space.

Readings

1. Particulates: Approximately 600 percent above EPA standard
Chinese safety standard for particulates: N/A (China doesn’t have this safety standard)
EPA safety standard for particulates: ≤.035 mg per cubic meter

Possible reasons for high levels of particulates: Possible causes include poor outdoor air quality, lack of air filtration, and cat dander.

What you can do about it: "Buy a stand-alone air filter that removes particulates," says Cheng, "and ventilate twice a day when outdoor levels are lower. If you have a cat, manage dander through brushing, bathing, and don't allow it near your bed.”

2. Formaldehyde: 25 percent over EPA standard
Chinese safety standard for formaldehyde: ≤.08 mg per cubic meter
EPA safety standard for formaldehyde: ≤.12 mg per cubic meter

Possible reasons for high levels of formaldehyde: The high levels of formaldehyde in this home are likely due to the family’s particle-board furniture.

What you can do about it: “Ventilate the particle board furniture outside," recommends Cheng. "Also add indoor plants that remove formaldehyde."

Shanghai apartment no. 2

This apartment, inside a Xuhui compound, was recently refurbished. The surrounding area is filled with shops, restaurants, and food stalls. No nearby factories.

Readings

1. Airborne Lead: 400-500 percent above EPA standard
Chinese safety standard for airborne lead: N/A
EPA safety standard for airborne lead: ≤.15 µg per cubic meter

Possible reasons for high levels of airborne lead: "The contaminant may have been tracked in from outdoors, as soil in the surrounding area tested at twice the allowable limit," says Cheng. Smoking indoors may also have contributed to the high levels as cigarette smoke contains lead.

What you can do about it: “Use a doormat and remove shoes before entering the house," notes Cheng. "We also recommended against any smoking in the house. Finally, a HEPA air filter would help filter out airborne lead.”

2. Particulates: 500-700 percent above EPA standard
Chinese safety standard for particulates: N/A
EPA safety standard for particulates: ≤ .035 mg per cubic meter

Possible reasons for high levels of particulates: Poor Quality of outdoor air, wearing shoes indoors, lack of any air filtration or HEPA vacuuming.

What you can do about it: “Start using a HEPA vacuum," he says. "HEPA air filter, and reduce external ventilation [opening windows] during peak traffic hours.”