A study published in the Journal of the American Heart Association found that blood vessels in healthy lungs became constricted after exposure to polluted air.

Researchers from the University of Toronto, tested 25 healthy volunteers with an average age of 35. The volunteers were exposed to ozone and fine particulate matter. After exposure, volunteers' blood vessels constricted between 2% and 4% on the average. Their vessels did not constrict when they were exposed to ozone-free and particle-free air.

The researchers used ultrasound to measure the diameter of the volunteers' brachial arteries that run from the shoulder to the elbow, before and after two hours of exposure to a concentrated mixture of ozone and fine particles. The level of 150 micrograms per cubic meter was about twice the level suggested by the U.S. Environmental Protection Agency (EPA) as safe for 24 hours of exposure to fine particles.

A chemical linked to cancer and other health problems has been discovered in sludge spread on farm fields in Wisconsin. Polychlorinated biphenyls (PCBs) levels as high as 920 parts per billion were found in recent testing of samples of recycled sludge from 50 sewage treatment plants in Wisconsin.

Although the levels are not alarming, the Clean Water Action Council was concerned about the risk posed by the PCBs as they are persistent in the environment and can accumulate up the food chain.

Playgrounds in numerous California neighbourhoods are not only becoming safer and more accessible to a wider range of kids but are also providing a second chance for many materials. These efforts are due to grants totalling more than US$2.5 million from the California Integrated Waste Management Board, the state's primary recycling agency and part of the state Environmental Protection Agency.

Scientists at San Diego State University (SDSU) are hitting California's beaches in search of waves but instead of surfing, these researchers are looking at the ocean as a source of renewable energy.

The California Energy Commission has awarded the university US$120,000 from its Public Interest Energy Research Program. A decade-old assessment by Pacific Gas & Electric Company found that about 23,000 MW of potential electricity was contained in the waves off the utility's service territory along California's north coast. The SDSU study will:

• see how much wave energy can be developed;
• compile a database of wave characteristics; and
• identify the critical factors for the development of wave energy, including the commercial status of wave-to-energy technology that is currently available.

Japan is racing to commercialise a new generation of fuel by 2006 to reduce greenhouse gas emissions and to rely less on Middle East energy imports.

Two separate Japanese joint ventures-one led by Mitsubishi Gas Chemical Inc and another by Japanese steelmaker NKK Corp-are aiming to begin mass production of dimethyl-ether (DME), which is commonly found in hair sprays.

DME, made from natural gas, emits no sulphur oxides or particulate matter and only small amounts of carbon dioxide.

Backers of DME say it could eventually replace liquefied petroleum gas (LPG) or gas oil as the main fuel for some vehicles and power generators. NKK's general manager of environmental solutions predicted that about 20% of Japan's imported LPG could be initially replaced by DME. Japan imports about 15 million tonnes of LPG a year. DME has similar properties as LPG, allowing it to replace LPG without too many adjustments to infrastructure.

Wei-xian Zhang, an associate professor of civil and environmental engineering at Lehigh University of Bethlehem has recently received a grant from the US Environmental Protection Agency to explore the potential for using nanoparticles to treat hazardous waste.

Nanotechnology involves pumping "nanoparticles" (about 100,000 would fit on the head of a pin) into the groundwater. With a composition that is 99.9% iron and less than 0.1% palladium, nanoparticles have large surface areas and a high rate of reactivity.

When applied to water or soil contaminated with carcinogenic solvents used in dry cleaning and industrial processes, nanoparticles remove chlorine and convert the solvents to harmless hydrocarbons and chlorides commonly found in table salt. The approach is dramatically more effective than traditional cleanup methods that require water to be pumped out, treated, then disposed of.

The Canadian Clean Power Coalition (CCPC) will research, develop, construct and operate a full-scale demonstration plant by 2007 to test the technical, environmental and economic viability of new clean coal technology for retrofitting existing coal plants.

This new technology promises to virtually eliminate air emissions of concern including carbon dioxide from coal burning power plants.

A zero emission, zinc-air fuel cell bus made its way to the nation's capital on 13 Mar 02 in a high-profile demonstration attended by government officials and journalists.

The demonstration of Electric Fuel's zinc-air fuel cell transit bus was being conducted to encourage political support for fuel cell technology in transportation and to help the company secure funding for a proposed zinc-air electric bus mini fleet project.

The fuel cell is capable of providing enough power to operate a regular-sized city bus for an entire day. The only major emissions from the bus are water and heat. It has a supplemental nickel-cadmium battery that provides an extra surge of power for acceleration. The battery stores electricity produced by the fuel cells when the bus stops and captures energy generated by the vehicle's braking system. Because it is a transmission-free vehicle, maintenance costs are expected to be relatively low - a large, centrally managed fleet would be only 10% more expensive to operate than a traditional diesel bus fleet.

New Japanese legislation mandating the cleanup of toxic sites is a triumph for environmental responsibility. The Tokyo ward has proposed a law to force corporations abandoning poisoned factory sites to take responsibility for the toxic messes they leave behind.

The legislation, which is expected to become law as soon as next January, would in some cases punish not the original polluters but the current owners of the blighted land. If the polluter is bankrupt and deemed incapable of paying for a cleanup - a potentially common occurrence - the current landlord could be held responsible for the entire bill.

The US Senate rejected a proposal to require utilities to produce as much as a fifth of their electricity from wind, solar, and other renewable energy sources.

The vote on renewables was the second setback for environmentalists in two days as the Senate considers a broad blueprint that would set the nation's energy policies. It had earlier defeated steep increases in auto fuel economy.

A proposal that would require 20% of electricity to come from non-hydro renewable sources by 2020 was rejected as critics called it too ambitious, unachievable, and too expensive.

Currently in the US, less than 2% of the electricity generated comes from renewable sources like solar panels, wind turbines, geothermal sources, or biomass such as wood waste, grasses or agricultural residues.

In a speech at Stanford University, BP's chief executive Lord John Browne announced that BP has reduced its greenhouse gas emissions by more than nine million metric tonnes over the past four years. In 1997, BP pledged to slash emissions from its own operations by 10% from 1990 levels by 2010. A goal now reached eight years early.

The company's emissions of carbon dioxide (CO₂) have fallen to almost 80 million tonnes, 10 million tonnes below 1990 levels and 14 million tonnes below the level they had reached in 1998.