Assessment of the chemical contamination in home-produced eggs in Belgium: General overview of the CONTEGG study

This overview paper describes a study conducted for the Belgian Federal Public Service of Health, Food Chain Safety and Environment during 2006-2007. Home-produced eggs from Belgian private owners of hens were included in a large study aiming to determine concentration levels of various environmental contaminants. By means of the analyses of soil samples and of kitchen waste samples, obtained from the same locations, an investigation towards the possible sources of contaminants was possible. Eggs, soils, faeces and kitchen waste samples were checked for the presence of dioxins, PCBs (including dioxin-like PCBs), organochlorine pesticides, trace elements, PAHs, brominated flame retardants and mycotoxins. The study design, sampling methodology and primary conclusions of the study are given. It was found that in some cases dioxin-like compounds were present at levels that are of concern for the health of the egg consumers. Therefore, measures to limit their contamination in eggs, produced by hens of private owners, were proposed and deserve further attention.     

Brominated flame retardants in Belgian home-produced eggs: levels and contamination sources

The extent and the sources of contamination with brominated flame retardants (BFRs), such as polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD), in home-produced eggs from free-foraging chicken of Belgian private owners were investigated. Various factors, such as seasonal variability, exposure of chickens through diet (kitchen waste) and soil, and elimination of BFRs through eggs and faeces were assessed. PBDEs were more important than HBCD in terms of concentrations and detection frequency. Concentrations of PBDEs and HBCD in Belgian home-produced eggs were relatively low and comparable with reported levels from other European countries and the US. The concentrations of PBDEs (sum of 13 congeners, including BDE 209) ranged between not detected and 32 ng/g lipid weight (lw), with medians of 3.0 and < 2.0 ng/g lw for the autumn 2006 and spring 2007 campaigns, respectively. When present, BDE 209 was the major PBDE congener (45% of sum PBDEs). When BDE 209 was not detected, the PBDE profile was composed of PentaBDE (BDE 99 and BDE 47), with, in some cases, higher contribution of OctaBDE (BDE 183 and BDE 153). HBCD was also detected (< 0.4 and 2.9 ng/g lw for the autumn 2006 and spring 2007 campaigns, respectively), but at lower detection frequency. The highest HBCD value was 62 ng/g lw. The similarity between profiles and seasonal variations in the concentrations of BFRs in soil and eggs indicate that soil is an important source, but not the sole source, for eggs laid by free-foraging chicken. The contamination of eggs with PBDEs and HBCD appears to be of low concern for public health and the contribution of eggs to the total daily intake of PBDEs appears to be limited (10% for chicken owners and 5% for the average Belgian consumer).     

PCDD/Fs and dioxin-like PCBs in home-produced eggs from Belgium: Levels, contamination sources and health risks

This paper discusses the dioxin TEQ levels as determined by the chemically activated luciferase gene expression assay (CALUX) and by HRGC-HRMS in eggs, soils, faeces and kitchen waste samples obtained in the CONTEGG study. The samples were collected in each Belgian province at private homes and in small gardens where chickens are held. The CALUX levels for eggs sampled in autumn were higher than the levels in eggs obtained at the same locations in spring (median values of 5.86 and 4.08 pg CALUX TEQ/g fat, respectively). The total WHO-TEQ levels in eggs, determined by HRGC-HRMS, ranged from 3.29 to 95.35 pg TEQ/g fat in autumn and from 1.50 to 64.79 pg TEQ/g fat in spring. In the soils on which the chickens forage, levels of 2.51-11.35 pg I-TEQ/g in autumn and 2.00-7.86 pg I-TEQ/g in spring were found. The congener pattern of PCDD/Fs in the eggs, soils and faeces was dominated by OCDD, in addition to 1,2,3,4,6,7,8-HeptaCDD, OCDF and 1,2,3,4,6,7,8-HeptaCDF. The predominant dioxin-like PCBs were PCB118, PCB 105 and PCB 156. The dioxin-like PCBs contributed on average 47%, 14% and 20% to the total WHO-TEQ in eggs, soils and faeces, respectively. Kitchen waste samples were very low-contaminated with dioxin-like compounds. The present results showed a good agreement between egg and soil TEQ levels for PCDD/Fs but not for dioxin-like PCBs. This study showed that current soil levels found in some private gardens do not lead to egg levels below the current EU maximal level of 6 pg total TEQ/g fat for dioxins and dioxin-like PCBs. The consumers of the analysed eggs attained 5-79% of the tolerable weekly intake (TWI) of 14 pg TEQ/kg bw for dioxins and dioxin-like PCBs by exposure to their home-produced eggs only.     

Trace elements in home-produced eggs in Belgium: Levels and spatiotemporal distribution

The purpose of this study was to evaluate the levels of arsenic, cadmium, lead, copper and zinc in home-produced eggs, soils and kitchen waste samples of private chicken owners in Belgium, and to determine spatiotemporal differences in trace element contents in eggs. Eggs were sampled in all provinces of Belgium in autumn 2006 and spring 2007. A total number of 59 private chicken owners participated in the study. Trace elements were determined by inductively coupled plasma-mass spectrometry except for mercury, which was determined by atomic absorption of mercury vapour. The mean fresh weight concentrations in eggs in autumn and spring respectively were < 8.0 and < 8.0 µg/kg for arsenic, 0.5 and < 0.5 µg/kg for cadmium, 116 and 74 µg/kg for lead, 0.43 and 0.52 mg/kg for copper, 20.3 and 19.2 mg/kg for zinc, and 3.15 and 4.44 µg/kg for mercury. Analysis of variance determined significant differences in some trace element concentrations in eggs among seasons and regions in Belgium. Average concentrations of arsenic, cadmium and mercury corresponded well with values measured in other countries, while copper and zinc concentrations were within the same order of magnitude as in other countries. Average lead concentrations were high compared to concentrations in eggs from other countries and correlated well with lead concentrations in soil, indicating that the soil is an important source. Other sources of trace elements in eggs might be home-grown vegetables and forage (grass and herbs), and indirectly, air pollution.     

PCB and organochlorine pesticides in home-produced eggs in Belgium

The level of polychlorinated biphenyls (PCB) and persistent organochlorinated pesticides (OC) in home-produced eggs was investigated in Belgium. The concentration of dichlorodiphenytrichloroethane (DDT) is above the norm for 17% of the eggs collected during the spring on 58 different locations. For PCB, aldrin, dieldrin, and chlordane, 3-5% of the samples are above the norm too. These levels are surprisingly high for compounds banned for about 30 years. Higher concentrations in home-produced eggs are expected compared to battery eggs because of contact with the environment and especially the soil. For ten selected locations, the concentration in soils, excreta and feed was measured, but no simple correlation between egg and feed or soil level could be established. Hexachlorohexane, endosulfan, endrin, methoxychlor and nitrofen were not detected in any sample.     

Mycotoxin analyses in some home produced eggs in Belgium reveal small contribution to the total daily intake

Low levels of deoxynivalenol (DON, range: 2.6-17.9 ng/g) and its metabolite de-epoxy-DON (DOM-1, range: 2.4-23.7 ng/g) were found in 20 home-produced egg samples collected in Belgium during autumn 2006 (from 10 breeders) and spring 2007 (same breeders). DON intake assessment showed that the consumption of these eggs may contribute to less than 1% of the provisional maximum tolerable daily intake of 1 μg/kg body weight established by FAO/WHO. None of the egg samples analyzed had quantifiable levels of zearalenone (ZEA), α-zearalenol, β-zearalenol, ochratoxin A (OTA) and citrinin (CIT). Intake of DON, ZEA, OTA and CIT via the consumption of home produced eggs seems not to be a matter of concern. Despite this, we recommend to continue in screening other eggs allowing to increase the sample size and the subsequent conclusion for mycotoxin contamination in eggs. As home produced food is generally not submitted to any compliance control and may be consumed in large quantities by their producers and other household members, it is worthwhile to further pay attention to the quality of feed as well as the environment in which the hens live.     

Feasibility of assessing dermal exposure to PAHs of workers on gaswork sites--the SOLEX study

Population exposure to pollutants in soil is an important public health concern. Difficult to measure, it is usually estimated using multimedia models. Modeling data predict that the skin surface is a predominant exposure route in roughly 15% of the US Superfund sites. Nonetheless, no study has confirmed these predictions. The SOLEX study was an opportunity to study the feasibility of estimating the cutaneous polycyclic aromatic hydrocarbons (PAHs: all 16 of the United States Environmental Protection Agency list) load of workers at three former manufactured gas sites, one of those being under remediation. Over two measurement periods (November 1997 and June 1998), 30 and 28 volunteers, respectively, were equipped for a single day work with five pads that collected soil particles and were placed at the neck, shoulder, wrist, groin, and ankle. Pad contamination was observed for six of the nine workers on the site being remediated but not on other sites. The wrist pad was most often affected, followed by the neck pad, these are, the exposed regions of the body. The PAHs most frequently identified were anthracene, fluoranthene, naphthalene, phenanthrene, and pyrene, at concentrations relatively high. In conclusion, this study showed that estimating skin exposure to soil pollutants is feasible. Secondly, it suggested that only subjects in close contact with the soil had a detectable exposure to PAHs. Extension of this approach to other exposure settings is warranted, especially among children playing in polluted public or private gardens, because their games lead to frequent contact with the soil.     

Large watershed management and restoration: dioxin sediment remediation case study

This paper reviews continuing, long-term remediation of river sediments containing dioxin and other chemical compounds in a large watershed of the Great Lakes Region. Chlorinated dibenzo-p-dioxins are a ‘family’ of chemically related compounds commonly known as chlorinated dioxins or simply, dioxins. The highest levels are usually found in sediments, soil and animal fats. The most toxic chemical in this group is 2,3,7,8-tetrachlorodibenzo-para-dioxin, the ‘standard’ to which other dioxins are compared and which has been shown to be very toxic in animal studies. The US Environmental Protection Agency (EPA) and Michigan Department of Environmental Quality (MDEQ) have made a lengthy effort to assess and remediate portions of the Saginaw Bay Watershed, including the Tittabawassee River. The paper reviews the EPA-proposed ‘phased approach’ to restoration and remediation of a short segment (Segment 1) of the Tittabawassee River sediments. Sediments are contaminated with a number of chemical pollutants other than dioxins, including arsenic, cholorbenzenes, cholorphenols, ethyl parathion, o-phenylphenol and polycyclic aromatic hydrocarbons. The paper evaluates three proposed ‘cleanup alternatives’, with final action method suggested based on effectiveness, feasibility for implementation and cost.     

Morphology of enamel in primary teeth from children in Thailand exposed to environmental lead

Lead is one of the major environmental pollutants and a health risk. Dental hard tissues have a capacity to accumulate lead from the environment. Eighty exfoliated primary teeth were collected from children residing around a shipyard area in southern Thailand, known for its lead contamination. The morphology of the enamel was examined by polarized light microscopy (PLM), microradiography (MRG), and scanning electron microscopy (SEM). The specimens derived from two groups of children, one group with high blood levels of lead (57 teeth) and one group having low blood levels of lead (23 teeth). The enamel irrespective of group appeared normal. However, in a majority of the specimens the enamel surface appeared hypomineralized, which was confirmed in SEM. No morphological changes connected to lead in blood could be found. The hypomineralized surface zone could possibly be attributed to an acid oral environment.     

Metal content of dandelion (Taraxacum officinale) leaves in relation to soil contamination and airborne particulate matter.

The global distribution of the common dandelion (Taraxacum officinale Weber, sensu lato; Asteraceae), along with its ability to tolerate a wide range of environmental conditions, make this 'species' a particularly attractive candidate to evaluate for its value as a biological monitor of environmental metal contamination. To examine the metal content of dandelion leaves in relation to environmental metal levels, the concentrations of eight metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) were analyzed in leaf and soil samples collected at 29 sites in the mid-western United States differentially impacted by pollution. Sites were chosen primarily to cover a range of annual mean 24-h airborne particulate matter < or = 10 microm (hereafter, PM10) exposure, with PM10 levels varying from those found in isolated rural areas to levels typical of the most industrialized urban locations in the mid-western United States. A positive. significant correlation was detected between soil concentrations of each metal and measures of PM10 at a site, signifying that airborne particulate matter is a good indicator of soil metal contamination. Leaf concentrations of four of the eight metals (Cr, Mn, Pb and Zn) examined were found to increase significantly as the soil levels of these metals increased, but the percentage of the total variation explained by the relationship in these cases was generally low. This latter finding, along with the lack of a significant relationship between leaf and soil concentrations for the four other metals, indicate that the factors affecting metal absorption from the soil by dandelions are complex and that, aside from soil metal concentrations, other soil, plant and/or other environmental factors affect metal uptake. There was also no evidence that leaf metal concentrations were positively correlated with PM10. In addition, the concentrations of some metals (Cu, Fe, Mn, Pb and Zn) were significantly higher in leaves collected in the fall compared to those collected at the same sites in the spring. These findings suggest that dandelions may not be a particularly effective tool for quantifying levels of environmental metal contamination, at least on the scale of pollution typifying industrialized urban areas of the mid-western United States.     

Biological monitoring of environmental contaminants: Chlorinated hydrocarbons in eggs of hens

High concentrations of persistent chlorinated hydrocarbon pesticide residues were detected by gas-liquid chromatography with an electron capture detector (³H), in eggs of hens collected from Lucknow under the pesticide monitoring programme. The present study reveals extremely high contamination of eggs, particularly with DDT and HCH residues. The eggs may be an important source of DDT and HCH build-up in the human body. Residue levels of p,p′-DDT and its metabolites p,p′-DDE and α, β and γ-isomers of HCH were higher in eggs of poultry-farm hens compared to those of domestic hens. Egg yolk contained higher levels compared with egg white, because of the lipophilic nature of pesticides and the high lipid content in the yolk. Average levels of total DDT and HCH residues in the yolk and white in the whole egg of a poultry-farm hen were found to be 18.5 and 4.6 μg respectively, whereas the average levels were 7.4 and 4.1 μg, respectively, in the whole egg of a domestic hen.     

Organochlorines in egg samples from Norwegian birds of prey: congener-, isomer- and enantiomer specific considerations

The content of chlorinated persistent organic pollutants was determined in a total of 44 egg samples from 8 different raptor species collected throughout Norway in the period 1991-1997. The content of 8 chlorinated bornanes, 9 chlorinated pesticides, and 15 polychlorinated biphenyl congeners (PCB) were determined. The highest average concentrations for PCB were found for eggs from White-tailed Sea Eagle and Peregrine Falcon (average sum PCB concentration: 8.9 and 9.1 microg/g wet weight (w.w.), respectively). Merlin and Sparrowhawk eggs were the highest contaminated with chlorinated pesticides (average sum pesticide concentration: 3.0 and 4.3 microg/g w.w.). For the first time, the content of chlorobornanes was determined in Norwegian birds of prey eggs. However, only minor contamination compared to PCBs and conventional chlorinated pesticides was found. The highest sum concentration was determined for White-tailed Sea Eagle eggs (0.09 microg/g w.w.). No chlorobornane contamination was found in Osprey and Merlin eggs. No spatial and regional specific trends or pattern distribution were found for organochlorine contamination in the egg samples analysed. In order to gain information about enantiomer specific bioaccumulation and biotransformation capacity of the organism, enantioselective analyses was performed for the chiral contaminants trans-chlordane, oxy-chlordane and the chlorobornane B9-1679 (Parlar #50). Indications for species-dependent deviation from the racemic distribution (enantiomeric ratio = 1) were found. Peregrine Falcon and Merlin eggs were characterised with an extremely high enantiomeric excess of the (-)-trans-chlordane (enantiomeric ratio (ER) <0.01). For Golden Eagle, Goshawk and Sparrowhawk eggs, the ERs were between 0.1 and 0.22 demonstrating also here that the (-)-trans-chlordane was the most abundant enantiomer. For the distribution of oxy-chlordane and B9-1679 enantiomers no species-dependent differences were found. For all species the ER values between 0.3 and 0.8 were determined. Thus, also for oxy-chlordane and B9-1679, the (-)-enantiomers are the most dominating stereoisomers in the birds of prey eggs analysed.     

An ecotoxicity assessment of contaminated forest soils from the Kola Peninsula

Point source copper and nickel contamination emanating from smelters of the Kola Peninsula, NW Russia, has been observed since the mid-1960s. Previous studies have concentrated on the spatial distribution of heavy metals and their effects on forest ecology and indigenous mammals and birds. Soil is perceived as the major repository for the metal pollutants but there is a need to link the soil concentration of pollutants on the Kola Peninsula with biological parameters. Many standard methods currently used in soil ecotoxicology are developed and refined with artificial amendments and rarely modified for use in historically contaminated environments. In this study, forest soils were sampled along a 34 km transect from the smelter and analysed both chemically and with a range of ecologically relevant biological tests. Soil respiration, total nematode count, microbial heterotrophic numbers and minimal inhibitory concentrations to copper and nickel were carried out on bulk soil. The soil pore water was tested with bacterial and fungal bioluminescence-based biosensors. The heterotrophic numbers and their inhibitory concentration showed strong correlation with heavy metal concentrations while decreasing biosensor luminescence was related to increasing copper concentrations present in the pore waters. Overall, there were considerable impacts on some microbial parameters but other measures including respiration and nematode populations were insensitive to pollutant levels. While chemical analysis of heavy metals proved essential in defining the extent of contamination, environmentally relevant ecotoxicological tests complemented these data by demonstrating pollutant impact. Ecotoxicological approaches that study both the bulk soil and pore water may represent the key to understanding the fate of heavy metal in soils.     

Methodology of hygienic standard-setting in the U.S.S.R

This article describes basic principles, criteria and methods of hygienic standard-setting for different environmental factors. It deals with hygienic standards for chemical pollutants in atmospheric air, water and soil, for bacterial and viral contamination, as well as for physical environmental factors with regard to their respective specificity. The article demonstrates the necessity of further development of methodology.     

Cadmium accumulation in different rice cultivars and screening for pollution-safe cultivars of rice

Large areas of contaminated land are being used for agricultural production in some countries due to the high demand for food. To minimize the influx of pollutants to the human food chain through consumption of agricultural products, we propose the concept of pollution-safe cultivars (PSCs), i.e. cultivars whose edible parts accumulate a specific pollutant at a level low enough for safe consumption, even when grown in contaminated soil. We tested the feasibility of the PSC concept by growing 43 cultivars of paddy rice (Oryza sativa L., including 20 normal and 23 hybrid cultivars) under a high (75.69-77.55 mg kg(-1)) and a low (1.75-1.85 mg kg(-1)) cadmium (Cd) exposure. These pot experiments took place in the spring and summer of 2004. At the low level of Cd exposure, 30 out of the 43 tested cultivars were found to be Cd-PSCs. Grain Cd concentrations were highly correlated (p<0.01) between the two experiments, suggesting that Cd accumulation in rice grain is genotype-dependent and that the selection of PSCs is possible, at least at a certain level of soil contamination. No Cd-PSCs were found under the high level of Cd exposure. Yield was enhanced in some cultivars and depressed in others in response to elevated soil Cd, indicating that farmers cannot rely on yield depression as an indicator of toxicity of the grains. It is therefore important and feasible to screen for PSCs and to establish PSC breeding programs to effectively and efficiently reduce the risk of human exposure to soil pollutants, such as Cd, through crop consumption.     

Monitoring of bacterial and parasitological contamination during various treatment of sludge

Wastewater treatment results in the production of large quantities of sludge. Agricultural use is an interesting alternative provided that the health risks are taken into account. In France, a decree (1998) defines "sanitized" sludge as sludge that has been treated so that pathogens (Salmonella, enteroviruses, viable nematode eggs) are no longer detectable. The aim of this study was to determine the impact of various sludge treatments on 2 types of pathogens (Salmonella and nematode eggs). We also assessed the levels of micro-organisms that indicate faecal contamination (E. coli, Enterococci, sulfite-reducing anaerobes spores). Various treatment processes were analyzed: 4 biological, 3 chemical, 1 heat, 2 storage and 4 sampling campaigns were carried out. Concerning the parasitological contamination of sludge at the entrance of all sites, concentrations of total nematode eggs and viable nematode eggs were highly heterogeneous (respectively, from 2 to 53 eggs/10 g DM and from 2 to 45 eggs/10 g DM) with viable eggs present in all samples. The total concentration of nematode eggs in the sludge was not greatly affected by treatment or storage, and was in the range < 1-66 eggs/10 g DM. However, the situation was different for mean viable egg counts. For four treatments, no viable eggs were detected. Mesophilic processes are inefficient at eliminating viable nematode eggs. Salmonella were systematically detected in all sludge samples at the entry to the station, except for limed sludge intended for storage. At the end of four treatments Salmonella had been totally eliminated. For the fecal contamination indicators, the largest decrease in E. coli contamination was observed following liming and after thermophilic treatment. The mesophilic treatments resulted in very small decreases in contamination. A similar pattern was observed with Enterococci. For the spores of sulfite-reducing anaerobe bacteria, with the exception of heat treatment, which reduced contamination by 3.2 log units, the maximum decrease in contamination was 1.7 log. For storage of sludge, E. coli and Enterococci levels had decreased at first but then increased between 6 and 8 months of storage.     

An evaluation of recent blood lead levels in Port Pirie,South Australia

The Port Pirie Lead Program commenced in 1984. The abatement program involves identification of children with elevated blood lead levels, house decontamination, soil treatment, development of heavily vegetated buffer zones around the smelter, family education and support and community education. Since 1984 the smelter has also implemented substantial new emission controls and environmental improvements. Blood lead and air monitoring programs as well as investigations of emission sources, ongoing household contamination and infant exposure mechanisms are in place. Although capillary blood lead monitoring has shown a significant decrease in the mean blood lead levels of the children, 61% of children aged 1-4 years still exceed 10 microg/dl, with 28% at or above 15 microg/dl. Re-entrainment of lead from the contaminated areas within the city is only a small contributor to air-borne lead levels compared with that from the smelter and its environs. The smelter has undertaken extensive work to reduce windborne fugitive emissions. While attempts to demonstrate reductions in air lead have been hampered by large annual variations in wind speed and direction, air lead studies have confirmed that only small losses are now arising from the stockpile area of the smelter site. Evidence suggests that worker hygiene improvements, relocation of children to lower exposure suburbs, community education, house decontamination, specific measures for individual children with elevated blood lead, and avoidance of tank rainwater have all been partially successful. A substantial investigation program has refocused intervention efforts towards reducing exposure from indoor environments during the first year of life and contributed to improved identification and ranking of ongoing smelter emission sources.     

Contamination of woody habitat soils around a former lead smelter in the North of France

The contamination of the topsoil of 262 woody habitats around a former lead smelter in the North of France was assessed. In this urbanized and industrialized area, these kinds of habitats comprise of hedges, groves, small woods, anthropogenic creations and one large forest. Except for the latter, which is 3 km away, these woody habitat soils often present a high anthropization degree (a significant amount of pebbles and stones related to human activities) with a high metal contamination. In the studied woody habitat topsoils, Cd, Pb and Zn concentrations largely exceeded those of agricultural topsoils located in the same environmental context. Therefore, atmospheric emissions from the smelter are not the only cause of the high contamination of the woody habitat soils. This last one is related to the nature and the contamination level of deposit in relation with human activities (rubbles, slag, soils, etc).With regard to the results obtained with chemical extractions, the mobility of Cd, Pb and Zn in these soils is also greater than in agricultural soils. In the forest, pollutant solubility is increased by soil acidic pH.The variability of the physico-chemical parameters and the high metal contamination of the topsoils are the main characteristics of the woody habitats located around the former smelter. Although never taken into account during risk assessment, the disturbance of these environmental components could have important biogeochemical impacts (nutrients and metal cycles). Moreover, any modification of the soils' use could potentially cause mobilization and transfer of the pollutants to the biosphere. Six years after the closure of the smelter, and as social and economic pressures considerably increase in this area, the study of these peculiar ecosystems is necessary to understand and predict the bioavailability, transfer, bioaccumulation and effects of pollutants in food chains.     

建筑施工中环境污染问题及防治措施

针对建筑施工过程所产生的扬尘、建筑泥浆等环境污染物进行分析,并提出了此类污染物应采取的管理对策和环境保护措施,从而最大限度地减少环境污染,保证人们有一个健康的工作、生活环境。