Soil

As spring phases into summer across the U.S., kids are spending more time outdoors. Playing outside is healthy in all kinds of ways, but it also poses some risks. One that many families may not be aware of is exposure to lead in soil, which is still a serious problem, mainly in cities. Children can be exposed to lead by swallowing or inhaling soil while they are playing. Young children often put their hands in their mouths and may have dirt on their hands. Kids and pets also can track lead dust from soil indoors. And anyone who eats fruit or vegetables grown in contaminated soil can ingest lead. Early in 2024, the U.S. Environmental Protection Agency lowered the screening level for lead in residential soils from 400 parts per million – a standard that was more than 30 years old – to 200 parts per million. This more protective lower number reflects current understanding of soil as a significance source of lead exposure for children. EPA officials said that at homes...

Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to curiouskidsus@theconversation.com. What is dirt? – Belle and Ryatt, ages 7 and 5, Keystone, South Dakota When you think about dirt, you might picture the rock dust that gets on your pants. But there’s so much more going on in the ground under our feet. When I began studying soil, I was amazed at how much of it is actually alive. Soil is teeming with life, and not just the earthworms that you see on rainy days. Keeping this vibrant world healthy is crucial for food, forests and flowers to grow and for the animals that live in the ground to thrive. Here’s a closer look at what’s down there and how it all works together. Soil is a vibrant ecosystem. Gabriel Jimenez via Unsplash, CC BY-SA...

With the arrival of spring in North America, many people are gravitating to the gardening and landscaping section of home improvement stores, where displays are overstocked with eye-catching seed packs and benches are filled with potted annuals and perennials. But some plants that once thrived in your yard may not flourish there now. To understand why, look to the U.S. Department of Agriculture’s recent update of its plant hardiness zone map, which has long helped gardeners and growers figure out which plants are most likely to thrive in a given location. The 2023 USDA plant hardiness zone map shows the areas where plants can be expected to grow, based on extreme winter temperatures. Darker shades (purple to blue) denote colder zones, phasing southward into temperate (green) and warm zones (yellow and orange). USDA Comparing the 2023 map to the previous version from 2012 clearly shows that as...

As the Arctic warms, its mighty rivers are changing in ways that could have vast consequences – not only for the Arctic region but for the world. Rivers represent the land branch of the earth’s hydrological cycle. As rain and snow fall, rivers transport freshwater runoff along with dissolved organic and particulate materials, including carbon, to coastal areas. With the Arctic now warming nearly four times faster than the rest of the world, the region is seeing more precipitation and the permafrost is thawing, leading to stronger river flows. Major river basins of the Arctic region. NOAA Arctic Report Card We’re climate scientists who study how warming is influencing the water cycle and ecosystems. In a new study using historical data and sophisticated computer models of Earth’s climate and hydrology, we explored how climate change is altering Arctic rivers. We found that th...

If humans are to establish long-term bases on the moon, they will need food resources. In recent years, scientists have been taking steps toward making moon agriculture possible. Researchers in China said this month that they have found a way to turn soil, that is similar to lunar soil, fertile. They found that introducing special bacteria into the soil can increase the amount of phosphorus, an important nutrient for plants. The Chinese scientists grew a plant that it is related to the tobacco plant in a laboratory in China. They used volcanic soil from the Changbai Mountains in Jilin province that is similar to moon soil, which scientists call lunar regolith. They treated the moon-like soil with three different kinds of bacteria. The researchers found that the plants raised in the bacteria-treated soil grew better than plants that grew in moon-like soil without the bacteria. The researchers said the bacteria made the soil more acidic. This permitted ph...