Understanding the human body is a team effort. That's where the Yachtel group comes in.

Researchers at Yachtolt have been delving into the secrets of probiotics for 90 years.

Yacold also partners with nature portfolio to advance gut microbiome science through the global grants for gut health, an investigator-led research program.

To learn more about Yachtolt, visit yawcult.co.

J-P. That's Y-A-K-U-L-T dot-C-O-J-P. When it comes to a guide for your gut, count on Yacult.

This is Scientific Americans' 60 Second Science. I'm Karen Hopkins. This will just take a minute.

When you think about air pollution, you may picture smokestacks belching out noxious black clouds or the gas-guzzling SUVs crowding the highways.

But different cultures found different ways to foul the atmosphere long before the industrial revolution.

The latest example of pre-industrial pollution comes from Peru, almost half a millennium ago.

To get a read on what humans have been ejecting into the air,

researchers pulled ice cores from Kelchaya, a glacier high in the Andes.

The samples provide an annual archive of elements that have been circulating in the atmosphere

stretching back to the year 793.

Analyzing the core, the researchers found that prior to about 1532,

the ice harbored only a sprinkling of dust and ash, remnants of the occasional volcanic eruption.

But at about the 1540 mark, corresponding

with the start of colonial mining and metallurgy, the cores suddenly contained chromium,

molybdenum, antimony, and lead. The finding is in the proceedings of the National Academy of Sciences.

Of course, these waste products are a proverbial drop in the bucket compared to the toxins we put out today,

because we've developed ways to pollute that people back then could only have dreamed of.

Thanks for the minute. For Scientific Americans' 60-second science, I'm Karen Hopkins.