There’s a trend that more city people decide that they want to grow crops and raise some live-stock (家禽). After all, there are few things more satisfying than biting into a bunch of tender, red carrots you grow yourself, or a fresh egg from the backyard.

Most gardeners understand that the soil in big cities is often polluted with lead and know to get their soil tested. But most are pretty clueless about how to prevent other types of pollutants, like heavy metals and asbestos(石棉)from getting into their vegetables.

Part of the problem is that “there might be pollutants that gardeners can’t test for,” says Brent Kim, a program officer. Most soil tests look for lead, cadrniunt(镉)and arsenic(砷). But they don’t test things like chemicals left behind by cars, which might have escaped into the soil.

So if you’re thinking of staring an urban garden, Kim says, once you’ve found a plot of land, you should learn what’s now an empty plot or a backyard might once have been a parking lot, a gas station or a chemical ground. “Knowing its past will give you some idea about what might be in that soil,” he says.

“People tend to think raised beds are going to solve their pollution problem,” Kim says. But polluted soil could easily kicked onto your plants, especially if the beds are low to the ground.

“Another consideration is that you have to be careful about the materials that you’re using to build a raised bed,” Kim says. Recycling wood from an old construction site might seem like a good, eco-friendly idea. But that wood could be treated with chemicals you don’t want touching your fruits and veggies, Kim says. And it’s always a good idea to use gloves while gardening, and wash all your produce thoroughly.

“I see these urban growing spaces as these oases(绿洲)in the middle of these urban environments,” Kim says. “They bring communities together, and they help people save money on fresh produce. Urban growing spaces are amazing. Let’s keep doing this, but let’s do it safely.”

D

     For starters, I was surprised when during our first conversational Hindi (印度语) lesson we learned the word for "thank you" doesn't really exist in Hindi. Okay, so there technically is a word, but it's really only recognized and used in the cities, where there is more of a Western influence.  In the mountains, it is seldom used, and what's more, people often seemed annoyed when we would try to thank them.  They would either turn their heads, or shake their hands at us as if to say, "Don't, it's not necessary."

     When we asked our Indian instructors why this is, they explained that giving and generosity are such complete aspects of their culture. In fact, it is part of the culture to view possession as a very unsteady thing. Giving is more of a matter of "changing hands" than an act of generosity. In their eyes, the cucumbers and other food they would give us were never really "theirs". They see them as having passed along to them and now they are simply passing them along to us.

     I believe there is a great sense of generosity in Western culture, but it seems to be more of a secondary thought. In other words, the viewpoint seems to be, "If I have enough, I will happily donate my surplus (盈余)."Whereas in the Himalayas, the villagers were eager to give away their best cucumbers to a passing stranger, and they would have happily given more even when it means less for them. In contrast, people in the U. S. tend to donate old, used, or unwanted items rather than their prized ones.

     Interestingly, during a coffee chat a couple of months ago, one of my friends, Josh Millburn, was telling me about how he donated his favorite clothes and shoes - just for the experience of giving up the possessions he likes most as well as to practice detaching (分派) for material things. So, this is something we as Westerners can certainly do, but it doesn't come wholly into our culture. It's something we have to make ourselves consciously aware of and push ourselves outside of our comfort zones to achieve.

Cell phones：Is there a cancer link?

Could your cell phone give you cancer? Whether it could or not, some people are worrying about the possibility that phones, power lines and Wi-Fi could be responsible for a range of illnesses, from rashes to brain tumors.

Some say there is evidence to support the growing anxieties. David Carpenter, a professor of environmental health sciences at the university at Albany, in New York, thinks there’s a greater than 95 percent chance that power lines can cause childhood leukemia (白血病). Also there’s a greater than 90 percent chance that cell phones can cause brain tumors. “It’s apparent now that there’s a real risk, ”said Carpenter.

But others believe these concerns are not justified. Dr Martha Linet, head of radiation epidemiology (流行病学) at the US National Cancer Institute, has looked at the same research as Carpenter but has reached a different conclusion. “I don’t support warning labels for cell phones, ”said Linet. “We don’t have the evidence that there’s much danger.”

Studies so far suggest a weak connection between EMFs (电磁场) and illness—so weak that it might not exist at all. A multinational investigation of cell phones and brain cancer, in 13 countries outside the US, has been underway for several years. It’s funded in part by the European Union, in part by a cell phone industry group. The final report should come out later this year, but data so far don’t suggest a strong link between cell phone use and cancer risk.

     How to deal with waste has been a problem since humans started producing it. As more and more people choose to live close together in cities, the waste-disposal（处理）problem becomes increasingly difficult.

       During the eighteenth century, it was usual for several neighboring towns to get together to select a faraway spot as a dump site. Residents or trash haulers（垃圾拖运者）would transport household rubbish, rotted wood, and old possessions to the site. Periodically（定期地）some of the trash was burned and the rest was buried. The unpleasant sights and smells caused no problem because nobody lived close by.
           Factories, mills, and other industrial sites also had waste to be disposed of. Those located on rivers often just dumped the unwanted remains into the water. Others built huge burners with chimneys to deal with the problem.

        Several facts make these choices unacceptable to modern society. The first problem is space.  Landfills(填埋场)are most needed in heavily populated areas. Such areas rarely have empty land suitable for this purpose. Property is either too expensive or too close to residential（住宅区的）neighborhoods. Long-distance trash hauling has been a common practice, but once farm areas are refusing to accept rubbish from elsewhere, cheap land within trucking distance of major city areas is almost nonexistent.

      Awareness（意识）of pollution dangers has led to more strict rules of waste disposal. Pollution of rivers, ground water, land and air is a price people can no longer pay to get rid of waste. The amount of waste, however, continues to grow.

       Recycling efforts have become commonplace, and many towns require their people to take part. However, even the most efficient recycling programs can hope to deal with only about 50 percent of a city’s reusable waste.