Lower-Emission Alternatives to Diesel for California Trucks
Engineering and environmental consultancy Ricardo, will partner with the Gas Technology Institute on two projects to help develop natural gas engines as a viable lower-emission alternative to diesel power for medium- and heavy-duty commercial vehicles on California highways. Diesel trucks can be major contributors to emissions of nitrogen oxides, greenhouse gases and diesel particulate matter. In the first project, Ricardo will test two different ignition systems—high frequency discharge and pulsed nano plasma—to gauge their effect on engine performance. The company will also support GTI in developing an ultra-low-emission natural gas engine for medium- and heavy-duty trucks. Such vehicles are currently among the top 10 sources of NOx emissions in California’s South Coast Air Basin. The trucks are projected to remain one of the largest sources, even as the legacy fleet of older and higher-polluting vehicles is replaced by vehicles that meet 2010 emissions standards.
Partial Water Pipe Replacement Holds Health Risks
A long-term simulation study confirms that partial replacement of lead pipes with copper, similar to what was undertaken in Flint, Mich., and Washington, D.C., can more than double the lead released into the water supply and increases the risk of lead exposure to harmful levels. Virginia Tech scientists reported the results of a four-year study designed to assess the impacts of three different water service line replacement configurations. Elevated lead from corrosion worsened over time for a configuration that used 50% copper. The researchers said that 140% more lead was released after 14 months. At high flow rates, all of the samples collected from combinations of lead and copper pipe exceeded health safety thresholds. That compared to zero risk for samples collected from 100% lead pipe.
Ultrasound Exposure Measured in Public Spaces
Research from the University of Southampton in the UK says that the public is being exposed unknowingly to high levels of ultrasound. This sound comes from sources such as loudspeakers, door sensors and public address systems. The exposure could result in illnesses ranging from migraines to chronic ringing ears. Using smartphones and tablets equipped with an app that produces a spectrogram of the microphone reading, Professor Tim Leighton collected readings of very high frequency/ultrasonic fields in public buildings during periods when they were heavily occupied. He found that the public is routinely exposed to VHF/US levels over 20 kiloHertz in areas such as railway stations, museums, libraries, schools and sports stadiums. The findings were calibrated with several independent microphone and audio data systems.