In other news from the Golden State, California could soon have the world’s toughest standards for emissions of microscopic pollutants. Regulations currently being considered by the state Air Resources Board target pollutants composed of particles of dust and soot that are smaller than 10 microns in diameter, or about one-seventh the diameter of a human hair. Such particles come from the agriculture industry and combustion in cars and power plants, and can contain heavy metals that contribute to lung, heart, and other health problems. Because of their tiny size, current filtering systems are not effective against them. The Air Resources Board estimates that 99 percent of Californians are exposed to unhealthy particle levels every day — but even if the board approves the strict regulations, the technology to keep such particles out of the air could take a decade or more to perfect.