Sentences with phrase «air concentrations exceed»

The models» composite annual mean OA surface air concentrations exceed 0.5 microgram of carbon per cubic meter across most continental regions, as shown at the left of Fig. 3, with maximum concentrations primarily over biomass burning regions and secondarily over industrialized areas.

Not exact matches

The study was conducted in Jena, Germany, a city with 100,000 residents and only a few days over the last several years during which concentrations of some air pollutants exceeded EU daily limits.

It also looked at whether an association between heart attacks and changes in air pollution exists in clean air cities where concentrations of air pollution vary but do not exceed EU limits.

«And we've shown that there are a number of times where the nitrogen dioxide (NO2) concentrations exceed the EU hourly mean limits for outdoor air quality.»

In addition, the results showed that dust concentrations during peak periods exceeded World Health Organization (WHO) air quality guidelines.

By contrast, U.S. cities exceed air quality standards when PM10 concentrations reach 150 micrograms per cubic meter.

(Everyday office air concentrations often exceed 1,000 ppm CO2.)

During extreme heat events, nighttime temperatures in the region's big cities are generally several degrees higher28 than surrounding regions, leading to increased heat - related death among those less able to recover from the heat of the day.36 Since the hottest days in the Northeast are often associated with high concentrations of ground - level ozone and other pollutants, 37 the combination of heat stress and poor air quality can pose a major health risk to vulnerable groups: young children, the elderly, and those with pre-existing health conditions including asthma.29 Vulnerability is further increased as key infrastructure, including electricity for potentially life - saving air conditioning, is more likely to fail precisely when it is most needed — when demand exceeds available supply.

Another study has found that idling vehicles do create serious pollution: «The concentration of air pollutants near schools may significantly exceed community background levels, particularly in the presence of idling school buses.»