We inhale, eat and drink toxic chemicals. Now we need to understand how they affect us.

These types of tests aren’t yet available to the public, but they’re being perfected in several labs, and researchers are working on ways to test even more chemicals.

That’s especially important because new chemicals are being developed all the time, and companies typically don’t need to put them through rigorous safety testing before they start using them, Marsit says. “They come to market almost every day,” he says. “(We have to) understand what they are, and what’s published, before we can even measure them.”

Understanding the health effects of these chemicals will take a lot of work. We often try to understand the impact of chronic exposures to low levels of pollutants, says Ian Mudway, who studies the health effects of air pollution at Imperial College London in the UK. “It’s like thinking about cigarettes,” he says. “Cigarettes don’t kill, but the long-term cumulative effect of the toxic load…advances disease.”

Determining a person’s long-term exposure to chemicals from blood or other body tissues is really difficult, Mudway says. Most measurements will only indicate a person’s short-term exposure.

Some researchers are working on personal sensors that can monitor a person’s exposure to a range of chemicals over time. And some of these sensors, such as air quality monitors, are available for purchase. But neither Mudway nor Marsit use them.

This is partly because they provide very limited information. An air quality monitor can tell you about the level of certain particles or indicate the airflow in a room. But it won’t tell you if or how these pollutants enter your body. This will likely depend on variables such as your breathing rate, your metabolism and the amount of skin exposed to air, says Mudway: “All of these factors become critically important.”

The most sensitive tests under development are, at this time, restricted to research labs – your doctor will not be able to perform them. Even if clinics could perform exposure testing, it would be difficult to know what to do with the results. As we strive to better measure our exposure to various chemicals, we still have a long way to go in understanding how they might affect our health.

“We can measure a lot of these (exposures), but, for a lot of these chemicals, we may not even know what the level of safety is,” Marsit says. Our estimates, even for relatively well-understood pollutants, can end up being wrong. “We tend to set a level of security, but in reality it ends up being much lower than that,” he says.