Three main groups of organic pollutants are accounted for in the Hungarian inventory: non-methane volatile organic compounds (NMVOC), persistent organic pollutants (POPs), and polycyclic aromatic hydrocarbons (PAHs).
NMVOC emissions are described in section Main pollutants.
Persistent organic pollutants (POPs) can be detected in nature for decades, because they are resistant to environmental degradation through chemical, biological, and photolytic processes. Their half-life is longer than two days in the atmosphere, two months in the waters, and six months in the soils. POPs typically are halogenated organic compounds, and exhibit high lipid solubility. For this reason, they bioaccumulate in fatty tissues of living organisms for long periods of time. These carcinogenic pollutants can travel long distances before being deposited. Traditionally certain chlorinated pesticides, industrial excipients, and highly toxic pollutants from combustion are included here. Polychlorinated biphenyls (PCBs), polychlorinated dibenzodioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) are reported in the inventory.
Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental pollutants generated primarily during the incomplete combustion of organic materials (e.g. coal, oil, petrol, and wood). The term 'PAH' refers to compounds consisting of only carbon and hydrogen atoms. Chemically the PAHs are comprised of two or more benzene rings bonded in linear, cluster, or angular arrangements. They are usually found as a mixture containing two or more of these compounds, e.g. soot. It has been proved that PAHs can cause carcinogenic and mutagenic effects and are potent immune-suppressants. Generally, PAHs enter the environment through various routes like improper residential heating methods, vehicle exhaust, industrial and forest fires, and smoking. Benzo[a]pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene, and indeno[123-cd]pyrene are reported in the inventory.
Figure 1. Long-term emission trend of organic pollutants between 1990 and 2019
Figure 1. presents the timeseries of POP and PAH emissions in Hungary. A decreasing trend can be seen at the beginning of the period due to the development of industrial abatement technologies (filters in the combustion of waste and dangerous materials) as well as to the restrictions in open burning of garden and other green waste in Hungary. Negative impact of energy poverty caused by the 2008 world economic crisis can be seen in the increase of emissions after 2008.
Main industrial sources of PCBs are steel production and non-ferrous metal foundry. The post-regime-change gradual decline of ferrous and non-ferrous industry in Hungary can be traced in the timeseries of this pollutant.
HCB emissions come from aluminium production, mainly from the so-called secondary aluminium foundry (recycling of aluminium waste). After the privatization of the Hungarian aluminium industry, the primary aluminium smelters processing bauxite were closed in 1996, and were replaced by secondary smelters after the regime-change. This process caused the rapid growth at the beginning of the period. After 1995, due to the development of abatement technologies in the secondary smelters, HCB emission started to fell. When the National POP Action Plan was born out of the Aarhus Convention, HCB emission measurements were made at the main Hungarian aluminium factory proving the low emission values from this industry.