AIR POLLUTION: 1992
National estimates of air pollutant emissions play an essential role in air resources management, both nationally and internationally. Consequently, the Ministry of the Environment, in cooperation with the Central Bureau of Statistics, has prepared national estimates of air pollutant emissions for the past several years. Following are the major findings included in the latest publication, updated for 1992 and compared with previous years. They include estimates on the countrywide quantities of air pollutants emitted into the atmosphere as a result of fuel combustion as well as data on concentrations of air pollutants (ambient air quality) in various regions in Israel from 1986-1992.
Sources and Methods of Calculation
Calculations of the quantities of air pollutant emissions are based on the following: data provided by the Central Bureau of Statistics on the annual consumption of the various types of hydrocarbon fuels and on the annual mileage made by the various types of vehicles and the publication entitled Air Pollutant Emission Factors published by the US Environmental Protection Agency (USEPA), updated for 1986.
For stationary sources (such as industry, households, etc.), the emission factor is the ratio (characteristic for a given human activity in which fuel of a given type is consumed) between the quantity of pollutant emitted to the atmosphere and the quantity of fuel consumed. For non-stationary sources
(vehicles), the emission factor is the ratio between the quantity of pollutant emitted to the air and the distance (in kilometers) covered by the vehicle.
The estimates on quantities of emissions of air pollutants were prepared in the Ministry of Environment. The indicatorsthe average quantity of air pollutant per capita (in kilograms) and the average quantity of air pollutant per square kilometer (in tons) were calculated by the Central Bureau of Statistics.
Concentrations of Air Pollutants
The source of these data is the national monitoring network which measures ambient air pollutants continuously throughout the year. Stations are distributed in the following population centers: Jerusalem, Haifa area, Hadera (Emek Hefer), Netanya, Dan metropolitan area (Tel Aviv, Petah Tikva), Ashdod and Beer Sheva. In addition to this monitoring network, which is operated by local authorities, the Israel Electric Corporation operates a monitoring network around its power plants in Ashdod, Tel Aviv, Haifa and Hadera.
The following data on air pollutant concentrations were collected from a selected number of the stations included in the national network (nine monitoring stations). These stations are located in the following areas: commercial urban centers in Jerusalem, Tel Aviv and Petah Tikva; industrial urban areas in Haifa; industrial suburbs in Ashdod, Hadera and Haifa; and residential suburbs in Netanya, Beer Sheva, and Hadera.
Data are initially stored at the monitoring station in the form of a 5-minute average, from which half-hour averages are calculated. These half-hour averages are used by the Air Quality Section of the Ministry of the Environment to calculate the following values:
* Average: annual concentration obtained by averaging the daily levels recorded during the whole year.
* Maximal daily value: the maximum daily value recorded during the year.
* Maximal half-hour value: The maximum half hour value recorded during the year.
In reviewing the data, it should be noted that Israeli ambient air quality standards (promulgated in 1971 and revised in 1992) differentiate between two types of standards: a statistical standard (or 99.75% standard), applying only to sulfur dioxide and defining the maximum permitted concentration for the pollutant 99.75% of the time; and an absolute standard (or 100% standard) which defines the maximum permitted concentration of an air pollutant, which must never be exceeded.
Major Findings: Air Pollutant Emissions
Carbon dioxide (CO2): In 1992, emissions reached 10.9 million tons, an increase of some 20% in comparison to average emissions during 1987-1991 (9.1 million tons), and a 72% increase in comparison to 1980 emissions (6.3%).
Carbon monoxide (CO): In 1992, emissions reached 601 thousand tons, 28% higher than the average quantity emitted during 1987-1991 (468 thousand tons), and more than double the quantity emitted in 1980 (284 thousand tons). The average quantity of carbon monoxide per capita reached 117 kilograms in 1992, as compared to an average of 102 kilograms per capita in 1987-1991, and 73 kilos per capita in 1980. The rise in carbon monoxide emissions is largely attributed to the dramatic increase in vehicle use.
Sulfur oxides (SOx): In 1992, emissions reached 290 thousand tons, compared to an average 274 thousand tons in 1987-1991. The average quantity of sulfur dioxide per capita reached 57 kilos in 1992, as opposed to 60 kilos per capita in 1987-1991 and 79 kilos per capita in 1980. The average quantity per kilometer reached 13.5 tons in 1992, as opposed to an average 12.7 tons in 1987-1991 and 15.2 tons per kilometer in 1980. The decrease noted in past years is due to the partial shift in electricity generation from high sulfur residual oil to low-sulfur coal.
Nitrogen oxides (NOx): Emissions have increased yearly and reached 171 thousand tons in 1992, as opposed to an average 141 thousand tons in 1987-1991 and 79 thousand tons in 1980. This increase is attributed to the increased consumption of gasoline and diesel; however it was partially offset by the decreased use of heavy residual oil and the switch to coal. The average quantity of nitrogen oxides per capita reached 33 kilograms in 1992 as opposed to an average 31 kilos in 1987-1991 and 20 kilos in 1980. The average per square kilometer reached 8.0 tons, as opposed to an average 6.6 tons per square kilometer in 1987-1991, and 3.9 tons per kilometer in 1980.
Hydrocarbons (HC): Emissions have increased yearly and reached 74 thousand tons in 1992, as opposed to 57 thousand tons in 1987-1991, and 34 thousand tons in 1980.
Suspended Particulate Matter (SPM): In 1992, emissions stood at 25 thousand tons, identical to 1987-1991 averages and just below the 1980 average (27 thousand tons). SPM emissions have not risen since the increase diesel fuel consumption by buses and trucks was offset by decreased consumption of heavy residual oil. The average quantity of particulates per capita decreased from 7.0 kilograms in 1980 to 5.6 kilograms in 1987-1991 to 4.9 kilograms in 1992.
Lead (Pb): In 1992, emissions reached 323 tons, compared to an average 407 tons in 1987-1991 and 432 tons in 1980. The decrease noted in 1988-1991 is attributed to the reduction in the lead content in gasoline.
Major Findings: Air Pollutant Concentrations
Sulfur dioxide: With the exception of Haifa and Ashdod, no violations of the absolute standard (1000 micrograms/cubic meter) were recorded during 1986-1992. While violations were recorded throughout 1986-1991, the highest concentrations were noted in 1990 in Haifa (2,623 mg/m3) and in Ashdod (2,462 mg/m3). Peak concentrations in 1992 were all below 1000 mg/m3 (945 mg/m3 in Petah Tikva, 819 mg/m3 in Ashdod and 610 mg/m3 in Tel Aviv). No violations of the statistical standard were recorded. The statistical standard allows for 45 episodes in which half-hour concentrations are between 500-1000 mg/m3.
Nitrogen oxides: During 1986-1992, violations of the absolute standard (940 micrograms/cubic meter) were recorded in Jerusalem and Ashdod. In Jerusalem, violations were noted in 1989-1991 with concentrations varying between 964-1064 mg/m3; in Ashdod, a violation was recorded in 1989 at 1,635 mg/m3.
Ozone: In 1992, violations of the absolute standard (230 micrograms/cubic meter) were noted in Jerusalem, Ashdod, Haifa and in Petah Tikva. The following concentrations were recorded: in the commercial center of Jerusalem312 mg/m3; in the industrial center of Ashdod283 mg/m3; in the industrial center of Petah Tikva234 mg/m3. The most severe violation ever recorded was noted in the industrial center of Hadera in 1985732 mg/m3.
Suspended Particulate Matter: During 1986-1991, violations of the standard
(200 micrograms/cubic meter) were noted in most areas. In 1992, the most blatant violations were in a residential area of Hadera, where the maximal concentration for 24 hours reached 704 mg/m3 and in the commercial urban center of Petah Tikva where the concentration reached 380 mg/m3 in the same year.