Emissions that are exhausted to the atmosphere take many forms: noise, gaseous pollutants, dust, or odours. Many are classified as nuisances of daily life, such as noise and odours. Some, however, are detrimental to the ozone layers or cause global warming. Criteria air contaminants such as sulphur dioxides (SO2), nitrogen oxides (NOX), volatile organic compounds (VOC) and particulate matter (PM), can have adverse effects on human health or the environment at high concentrations. The services SENES provides are the assessment, measurement, modelling, inventory, or abatement of these types of emissions.