HCB,PCB, PCDD and PCDF emissions from ships

Since current estimates of hexachlorobenzene (HCB), polychlorinated biphenyls (PCB), dioxins (PCDD) and furans (PCDF) from ships are based on a relatively limited and old data set, an update of these emission factors has been outlined as a target towards improved Swedish emission inventories. Consequently, a comprehensive study was undertaken focusing on these emissions from three different ships during December 2003 to March 2004. Analyses were performed on 12 exhaust samples, three fuel oil samples and three lubricating oil samples from a representative selection of diesel engine models, fuel types and during different “real-world” operating conditions.The determined emissions corresponded reasonably well with previous measurements. The data suggest however that previous PCDD/PCDF emission factors are somewhat higher than those measured here. As expected the greatest emissions were observed during main engine start-up periods and for engines using heavier fuel oils. Total emissions for 2002, using revised emission factors, have been calculated based on Swedish sold marine fuels and also for geographical areas of national importance. In terms of their toxic equivalence (WHO-TEQ), the PCDD/PCDF emissions from ships using Swedish fuels are small (0.37–0.85 g TEQ) in comparison to recent estimates for the national total (ca. 45 g TEQ). Emissions from other land-based diesel engines (road vehicles, off-road machinery, military vehicles and locomotives) are estimated to contribute a further 0.18–0.42 g TEQ. Similarly, HCB and PCB emissions from these sources are small compared to 1995 national emission inventories.     

PCDD/PCDF contamination following a plastics fire in a university lecture hall building

Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were detected in soot from a building fire involving synthetic materials not containing polychlorinated biphenyls (PCBs) or chlorobenzenes.     

PCDD, PCDF, AND PCB concentrations in human milk from two areas in Finland

Concentrations of 17 toxic 2,3,7,8-chlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and of 36 polychlorinated biphenyl congeners (PCBs) were analyzed from 167 randomly sampled human milk samples from Southern (77 samples) and Eastern (90) Finland. The level of PCDD/Fs and PCBs in human milk in Southern Finland was about 25% higher than those from Eastern Finland. The level of PCDD/Fs in human milk in Finland was the same as in Sweden, 30–50 % lower than in milk from Central Europe but about 45% higher than values from Norway or Russia. The PCB concentrations in Southern Finland were at the same level as in the Netherlands, and in Eastern Finland at the same level as in Norway. The levels of PCDD/Fs and PCBs decreased with increasing number of children: the third child was exposed to about 70% of the amount of PCDD/Fs and PCBs as compared with the first child, and the eighth to tenth child to about 20%. The congener patterns of PCDD/Fs and PCBs in Finnish human milk were similar to the countries of Central Europe, however, the levels of penta- and heptachlorinated furans were slightly higher than in milk from other countries.     

Temporal trends and spatial distribution of PCDD, PCDF, and PCB in pine and spruce shoots

In Germany, there is a lack of consistent and comparable data for the time dependent behaviour and spatial distribution of dioxin-like and indicator PCB in ambient air, deposition and plants. The aim of this study was to improve the data on PCDD/PCDF, dioxin-like PCB and non dioxin-like PCB in spruce and pine shoots from different locations and years by retrospective monitoring. The survey was conducted with archived samples of one-year old spruce shoots (Picea abies) and pine shoots (Pinus sylvestris) from the German environmental specimen bank. Two sets of samples from locations in urbanized areas in western and eastern Germany (Warndt and Duebener Heide Mitte, respectively) were investigated as time series. Additionally, spruce shoots from seven different rural locations sampled in the years 2000-2004 were analyzed in order to get an overview about the spatial distribution of PCB and PCDD/PCDF. The analytical results of the samples from the two urbanized areas clearly show that the atmospheric contamination with PCDD and PCDF has declined by about 75% between 1985 and 1997 at Warndt and about 40% between 1991 and 1997 at Duebener Heide. However, concentrations stayed virtually constant at both locations from 1997 to 2004 at a level of about 1 ng WHO-TEQ/kg dry matter (d.m.). Similarly, the investigation of spruce shoots from rural locations from 2000 to 2004 did not reveal a temporal trend at any site. PCDD/PCDF levels were between 0.1 and 1.0 ng WHO-TEQ/kg d.m. At the urbanized location Warndt the six indicator PCB as well as the 12 dioxin-like PCB according to WHO revealed a significant decline by more than 75% between 1985 and 1999. Thereafter, PCB levels stayed virtually constant. At the location Duebener Heide an overall decrease of PCB concentrations in pine shoots of about 60% was detected between 1991 and 2004. Spruce shoots from all locations showed a relevant contribution of dioxin-like PCB to the total WHO toxicity equivalent (PCDD/PCDF+PCB). In most samples, the contribution of dioxin-like PCB was between 21% and 41%. The TEQ contribution of PCB in the samples from three rural sites was higher and similar to the TEQ value of PCDD/PCDF. The investigated pine shoots from the urbanized site Duebener Heide showed a 15-28% contribution of dioxin-like PCB to total TEQ and thus lower than in spruce shoots from different locations. In all samples except one PCB 126 contributed to more than 80% to the PCB-TEQ.     

Dechlorination and destruction of PCDD,PCDF and PCB on selected fly ash from municipal waste incineration

The potential of fly ash to dechlorinate and destroy PCDD, PCDF and PCB was tested under oxygen deficient conditions in the laboratory. Specifically, two types of fly ash were compared, originating either from a fluidized bed incinerator using Ca(OH)₂ spray (FA1), or a stoker incinerator without Ca(OH)₂ impact (FA2).

Results from the present study indicate that on FA2 type fly ash, the degradation processes of OCDD, OCDF and D₁₀CB occurred primarily via dechlorination/hydrogenation up to temperature settings of 340 °C. In contrast, FA1 type fly ash was found to effect both dechlorination and destruction of these compounds already at temperature settings of 260 °C.

The dechlorination velocity of PCDD and PCDF did not differ significantly. However, the first dechlorination step of OCDF in the 1,9-position occurred faster compared to the first dechlorination step of OCDD.

The isomer pattern resulting from the dechlorination processes was quite similar on both FA1 and FA2, indicating that differences in alkalinity or elemental composition of the two types of fly ashes do not have a significant influence on the position of dechlorination. PCDD and PCDF dechlorination of the 2,3,7,8-positions was not favoured over dechlorination of the 1,4,6,9-positions on either type of fly ash. In contrast, dechlorination of PCB occurred predominantly on the toxicological relevant 3- and 4-positions.

The dechlorination/destruction processes were completed on both types of fly ash at 380 °C within one hour, which correlates well with results obtained from actual plant operation practices.     

PCBs fires: Correlation of chlorobenzene isomer and PCB homolog contents of PCB fluids with PCDD and PCDF contents of soot

PCBs, PCDDs, and PCDFs are subject to new regulations promulgated under the Toxic Substances Control Act and the Resource Conservation and Recovery Act. The finding of PCDDs and PCDFs in PCBs could restrict disposal options for PCBs. A review of major fire incidents in the U.S., indicates that PCDDs have been found only in the Binghamton, N.Y., transformer fire incident. Laboratory combustion studies further support PCDFs formation from PCBs and PCDDs from chlorobenzenes. No PCDDs were found in analyses of fluids from transformers involved in transformer fire incidents. PCDFs do not appear to increase in PCBs askarel fluids from normal usage in electrical equipment.     

PCDD, PCDF, PCB and PBDE concentrations in breast milk of mothers residing in selected areas of Slovakia

The concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dioxin-like polychlorinated biphenyls (dl-PCBs) and polybrominated diphenylethers (PBDEs) in 33 breast milk samples collected in 2006-2007 from primipara mothers close to four industrial areas of Slovak Republic were determined. The total PCDDs/PCDFs and dl-PCBs expressed as TEQ based on WHO TEFs 1998 in breast milk samples varied from 5.0 to 51.8 pg g⁻¹ fat (median: 13.1 pg g⁻¹ fat; mean: 18.0 pg g⁻¹ fat). The measurements of seven PBDE congeners (IUPAC No. 28, 47, 99, 100, 153, 154, and 183) were performed for the first time in human milk from Slovakia. PBDE levels ranged between 0.22 and 1.62 ng g⁻¹ fat, with median and mean value of 0.43 ng g⁻¹ fat and 0.57 ng g⁻¹ fat respectively. No statistically significant differences were observed between studied areas in total PBDE concentrations.Furthermore, this study presents first results concerning the daily intake (DI) of PCDDs/PCDFs and dioxin-like compounds for the most vulnerable breast-fed infant population in Slovakia. The total PCDD/PCDF and dl-PCB DI for an infant during the first 2 months of life was estimated in a range from 14.4 to 230 pg TEQ kg⁻¹ b.w., with a median value of 58.9 pg TEQ kg⁻¹ b.w.. The DI values substantially exceeded the tolerable daily intake (TDI) 1-4 pg TEQ kg⁻¹ b.w. recommended by WHO. The dietary infant intake concerning PBDEs was estimated to be between 0.69 and 7.1 ng kg⁻¹ b.w. d⁻¹, with median value of 1.7 ng kg⁻¹ b.w. d⁻¹.     

The effect of oils on PAH, PCDD, PCDF, and PCB emissions from a spark engine fueled with leaded gasoline

The effect of synthetic and mineral oils on the formation of polyaromatic hydrocarbons (PAHs), polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and biphenyls (PCBs) in emissions from a spark ignition engine was studied on a Skoda Favorit engine fueled with leaded gasoline. The test cycle simulated urban traffic conditions on a chassis dynamometer, in accordance with the ECC 83.00 test. The data for selected PAHs as well as PCDDs, PCDFs, and PCBs congener profiles are presented. PCDD/Fs emissions for an unused oil and the oil after 10000-km operation varied from 300 to 2000 fmol/m3, PCBs emissions from 75 to 178 pmol/m3, and PAHs emissions from 150 to 420 microg/m3. The content of PCBs in oils varied from 2 to 920 mg/kg.     

Open burning of household waste: Effect of experimental condition on combustion quality and emission of PCDD, PCDF and PCB

Open burning for waste disposal is, in many countries, the dominant source of polychlorinated dibenzodioxins, dibenzofurans and biphenyls (PCDD/PCDF/PCB) release to the environment. To generate emission factors for open burning, experimental pile burns of about 100 kg of household waste were conducted with emissions sampling. From these experiments and others conducted by the same authors it is found that less compaction of waste or active mixing during the fire - “stirring” - promotes better combustion (as evidenced by lower CO/CO₂ ratio) and reduces emissions of PCDD/PCDF/PCB; an intuitive but previously undemonstrated result. These experiments also support previous results suggesting PCDD/PCDF/PCB generation in open burning - while still highly variable - tends to be greater in the later (smoldering) phases of burning when the CO/CO₂ ratio increases.     

A study on PCB, PCDD/PCDF industrial contamination in a mixed urban-agricultural area significantly affecting the food chain and the human exposure. Part I: soil and feed

This study deals with a PCB, PCDD and PCDF contamination in Brescia, a city in the North-West of Italy, affecting an area with about 11000 inhabitants. The area is close to an industrial plant that produced, in total, some 31,000 ton of PCB. A relevant part of the polluted area is agricultural soil, where cattle were fed with polluted forage and farmers were consuming their own products, so that contamination led eventually to human exposure. Total levels of PCDD/Fs varied from 8 to 592 pgTE(WHO)/g for soil samples and when the dioxin-like PCBs (dl-PCBs) are included, the levels varied from 14.6 to 1033.7 pgTE(WHO)/g. In several cases, the legal limit was exceeded by more than one order of magnitude, with the highest contamination in some agricultural areas and in the surrounding zones. For the forage samples, total levels of PCDD/Fs varied from 0.29 to 2.04 pgTE(WHO)/g and, when dl-PCBs are included, this range increased from 2.04 to 4.75 pgTE(WHO)/g. PCB contamination of the forage through vapor condensation seemed to be relevant. The toxic contribution of dl-PCBs is always relevant and must be considered for risk management. The main component of the contamination source is probably a heavy PCB mixture, such as Aroclor 1262. The study dealt generally with the contamination transfer of PCBs, PCDDs and PCDFs from soil up to humans across the food chain. Results on soils and forages are shown, while measurements concerning the contamination of the animals fed with contaminated forage, and the exposure of the farmers (through human serum analyses), as compared to general population, will be reported in a dedicated paper.     

Sources and fate of PCDD and PCDF

PCDD and PCDF were found in urban air particulates from St. Louis and Washington, D.C., and in sediments from the Great Lakes and Siskiwit Lake, Isle Royale. The similarity between the PCDD and PCDF found in air particulates and sediment samples and the presence of PCDD and PCDF in sediment from Siskiwit Lake (a location which can receive only atmospheric inputs) suggest that these compounds are emitted to the atmosphere from combustion sources. The historical input of PCDD and PCDF to dated sediment cores shows a strong increase since 1940, and this suggests that the incineration of chlorinated organic compounds is an important source of PCDD and PCDF to the environment.     

Formation of PCDF, PCDD, PCB, and PCN in de novo synthesis from PAH: mechanistic aspects and correlation to fluidized bed incinerators

The difference of polychlorinated dibenzofurans (PCDF) isomer patterns between stoker type incinerators and some fluidized bed incinerators (FBI) is a key to understand the formation mechanisms in both types of incinerators. The total yield and the isomer patterns of PCDF, polychlorinated biphenyls (PCB), polychlorinated naphthalenes (PCN), and polychlorinated benzenes (PCBz) formed via de novo synthesis from polycyclic aromatic hydrocarbons (PAH) indicate that chlorinated aromatics in the FBI are formed as a result of PAH breakdown. The detailed analysis of the isomer patterns of PCDF, PCB and PCN gives a first insight into the transformation mechanism of the PAHs and the sequence of degradation, chlorination and oxygen insertion. The major chlorination takes part at the position of the C-C cleavage during degradation of the PAHs. Further chlorination of the hydrogen position of the former PAH takes part preferably in ortho-position to this chlorination or is directed by incorporated oxygen. A perylene structure in soot is proposed as basis for the observed PCDF pattern in the FBI. Polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated phenols (PxCP) were formed in lower concentrations from the de novo experiments indicating an additional formation pathway for these compounds in the FBI.     

PCDD/PCDF,chlorinated pesticides and PAH in Chinese teas

Four samples of Chinese tea (two green teas, and two brick teas) were analyzed for their concentrations of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/PCDF), chlorinated pesticides and PAH. The infusions prepared from these teas were also analyzed for PCDD/PCDF. The levels of DDT and its metabolites in tea leaves were within the safety limit of 0.2 mg/kg. Rather high levels of total PAH were obtained in brick tea (1048–1162 mg/kg), when compared with green tea (497–517 mg/kg). In terms of PCDD/PCDF, the concentrations of green tea and brick tea differed by a factor of 16, while the concentrations of all infusions were within a factor of 2. The dioxin concentrations in green tea leaves can be explained through uptake of atmospheric PCDD/PCDF. The higher concentrations in the brick tea leaves are due the longer exposure time, and to certain extent, the use of old leaves, branches and roots when making the tea, and additional components such as soil particulates through contamination. Certain Chinese populations drinking a large amount of brick tea (>3 l per day) indicated that individuals of these populations consume more tea than Europeans or North Americans result in a comparably higher intake of PCDD/PCDF. Tea consumption can attribute to up to 10% of the TDI recommended by WHO (only PCDD/PCDF considered, no PCB analyzed).     

Analytical procedures to assay environmental samples for PCDD/PCDF, PHA, PCB, chlorobenzenes (CB) and chlorophenols (CP)

Sample extracts from each section of a blank stack sampling train are portioned into two fractions, one to be used for PCDD/PCDF and PCB/CB analysis and the other for PAH/CP. The results of recovery studies for spiked compounds are presented. Developed protocols will be applied to future stack sampling programs and other environmental monitorings.     

Formation characteristics of PCDD and PCDF during pyrolysis processes

In recent years, pyrolysis processes have become technologies developed to industrial scale and discussed as alternatives to the existing waste combustion technology. However, little information is published regarding PCDD/F formation characteristics during pyrolysis processes. Two common shredder fractions – industrial light shredder (ILS) and refrigerators (REF) – both with high chlorine and copper content were pyrolysed for this pyrolysis study using a pilot plant with a capacity of 100 kg/h. At oxygen concentrations below 2% and temperatures between 430°C and 470°C, considerable amounts of PCDD/F were formed during the pyrolysis. More than 90% of total TEQ was found in the oil fraction (gas phase). The PCDD/PCDF ratio and the homologue pattern differed significantly from those formed during waste incineration. Considering mono- to octachlorinated congeners, up to 400 times more PCDF were formed compared to PCDD. For the investigated pyrolysis conditions, the formation of low chlorinated congeners was highly favoured. The distribution of TEQ within the individual congeners were very similar in all investigated runs. More than 80% of total TEQ stem from 2,3,7,8-substituted T₄CDF and P₅CDF. The isomer pattern, however, did not show significant differences compared to the common waste incineration pattern suggesting that the basic formation routes are similar.     

Pentachlorophenol (PCP), PCDD,PCDF and pesticide concentrations in a freshwater lake catchment

The concentrations of pentachlorophenol (PCP), polychlorinated dibenzo-p-dioxins (PCDDs) polychlorinated dibensofurans (PCDFs) and organochlorine and organophosphorus pesticides in water, sediments and biota from the Lake Rotorua catchment were determined to evaluate the relative significance of various contaminants and their potential sources. PCP was found in water, sediments and biota (fish and freshwater mussels) and the highest concentrations in water (3.62 μ g.L⁻¹) and in sediments (400 ng.g⁻¹ dry weight (DW) were found in and near a stream that had been affected by PCP contamination from a sawmill. PCDD and PCDF concentrations in all cases, except for the waters and sediments of the stream near to the sawmill, were relatively low compared to values reported in the literature for similar sites. Negligible pesticide contamination was found in the Lake Rotorua catchment. Pesticides found included low concentrations of p.p′-DDE, p.p-TDE and dieldrin in rainbow trout from the lake.     

Human PCDD/PCDF levels near a pentachlorophenol contamination site in Tainan, Taiwan

A pentachlorophenol (PCP) manufacturing plant in southern Taiwan discontinued production in 1989. The site of the abandoned plant was heavily contaminated by PCDD/PCDFs, impurities formed in the PCP production process. Serum samples collected from 27 residents living near the deserted plant were evaluated to determine whether this contamination had associated serum levels of PCDD/PCDFs in local residents. The average level of 17 tested congeners ranged from 556 to 5240 pg/g lipid (mean, 1670 pg/g lipid). The corresponding 2,3,7,8-TCDD toxicity equivalent quotient values calculated by international toxicity equivalent factors (I-TEFs) and those recommended by WHO (WHO-TEFs) were 47.2 pg I-TEQ/g lipid and 53.4 pg WHO-TEQ/g lipid, respectively. Levels in other parts of Taiwan typically range from 15 to 20 pg WHO-TEQ/g lipid; therefore, it is likely that the heavily contaminated plant site caused these unusually high serum levels. The average PCDD/PCDF levels of 29 fish-tissue and nine soil samples collected from the sea reservoir surrounding the abandoned PCP plant were also abnormally high: 8630 pg/g lipid (985 pg WHO-TEQ/g lipid) and 606000 pg/g-sample (922 pg WHO-TEQ/g-sample), respectively. Factor analysis indicated that the congener pattern of human serum samples collected from residents living near the abandoned PCP plant different from samples collected from other areas in Taiwan without known PCDD/PCDF pollution. Similar results were observed for the fish tissue and soil samples. The current study may have discovered a "hot spot" for elevated dioxin human exposure in Taiwan. The preliminary finding has raised a public health concern in the inspected area and requires further investigations to clarify the nature of the contamination and potential impact on the local environment and human health.     

PCDD/PCDF, dl-PCB and PBDE serum levels of Slovak general population

Blood serum specimens from 81 non-occupationally exposed adults residing in four areas close to municipal and waste incinerators as well as metallurgical industry plant and 44 adult subjects coming from control area of Slovakia were analysed for polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dioxin-like polychlorinated biphenyls (dl-PCBs) and polybrominated diphenylethers (PBDEs). The concentration of total WHO(98)TEQ PCDD/F/dl-PCBs in whole group of donors from areas where known sources causing dioxin contamination are present was significantly higher than in control group of donors (p<0.001). Correlation between the age of donors and PCDD/F and dl-PCB levels was confirmed (Spearman's r(PCDD/Fs)=0.543, r(dl-PCBs)=0.521, p<0.001). Furthermore, this study presents first results concerning the PBDE congeners in human serum of Slovak general population. The total concentration (congeners 28, 47, 99, 100, 153, 154, 183) in control group was approximately 1.5-times higher in comparison to that of residents coming from areas with supposed environmental pollution. The most abundant congeners in all samples were BDE-47 and BDE-153 with median values of 0.24 ng g(-1) lipid and 0.23ngg(-1) lipid, respectively. The positive association between PBDE values and age of donors was not found.     

Comparison of PCDD/PCDF levels in soil, grass, cow''s milk, human blood and spruce needles in an area of PCDD/PCDF contamination through emissions from a metal reclamation plant

When in the vicinity of a metal reclamation plant in Tyrol, Austria, increased PCDD/PCDF levels were found in soil and spruce needles, the extent of grass contamination as well as the PCDD/PCDF content in milk of cows fed with hay from this area was determined. The milk samples showed a significant increase in PCDD/PCDF levels compared to control samples. In a blood sample of a farmer a significant increase in PCDD/PCDF levels was found. Correlations in PCDD/PCDF levels between soil, spruce needles, grass, cow's milk and human blood will be presented.     

Concentrations of PCDD/PCDF in soil close to a secondary aluminum smelter

Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDDs/Fs) were analyzed in samples of the emissions from a secondary aluminum smelter (ALS) and soil samples around the plant. The purpose was to estimate the impact of the emissions on the surrounding environment.PCDD/F soil concentrations were higher in the proximity of the plant, exceeding the limit adopted in Italy in soils for green areas and residential uses and the upper limit of several reference concentrations. The most contaminated sites were less than 500 m from the plant and the dioxin concentration with the distance from the ALS.Principal component analysis (PCA) showed that emissions from the ALS were the source of PCDD/F contamination in the soils closest to the plant. Multivariate data analyses such as PCA are therefore useful to identify sources of emission causing contamination.