Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in adipose tissue of women from Grand Tunis and their association with demographic factors and dietary habits.

Dichlorodiphenyl trichloroethane and its metabolites (DDTs), hexachlorocyclohexane isomers (HCHs), hexachlorobenzene (HCB) and polychloronated biphenyls (PCBs) were measured in 25 woman adipose tissues collected in 2016 from Grand Tunis, Tunisia. p,p'-DDE, p,p'-DDT, HCB and ß-HCH were the dominant organochlorine pesticides (OCPs) in decreasing order in all samples. The total OCP levels varied from 79 to 343 ng g-1 lipid with a median value of 189 ng g-1 lipid and DDTs contributed approximately 88% to sum OCP. The ratio of p,p'-DDT/p,p'-DDE across all samples is below one, which suggests mainly historic exposure but may indicate some recent exposure to the banned pesticide. The median concentration of PCBs was 109 ng g-1 lipid and ranged between 27 and 204 ng g-1 lipid. PCB-153, PCB-180, PCB-138 and PCB-170 were the most abundant congeners, which contributed about 78% of the total PCBs. Spearman analysis showed that dominant organochlorine compounds (OCs) are highly positive correlated except for PCB-28/31, indicating that women from Tunis are exposed via similar routes. Inhalation exposure could be a possible pathway for the uptake of the less chlorinated congeners. We found positive and statistically significant association with subjects age for HCB (r = 0.517; p = 0.009) and PCBs (r = 0.65; p = 0.001) levels and a weak age-dependent accumulation was found for HCHs (r = 0.375; p = 0.065) and DDTs (r = 0.388; p = 0.056). The concentrations of OC subgroups were not associated with BMI, parity and residence. No association was observed between fish, red/white meat, milk and dairy products consumption and levels of HCB, HCHs and PCBs. DDTs levels were significantly correlated only with milk (p = 0.048) and milk products (p = 0.047) intake.

Organochlorine pesticides and polychlorinated biphenyls in raw bovine milk from various dairy farms in Beja, Tunisia: contamination status, dietary intake, and health risk assessment for the consumers.

We determined organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in raw bovine milk taken directly from the milking equipment for different animals and various farms in Béja region, which is one of the largest milk producing areas in Tunisia. All milk samples were contaminated with one or more pesticides and exhibited measurable concentrations of some PCB congeners. The residue levels are generally marked by the predominance of dichlorodiphenyltrichloroethanes (DDTs) (median: 17.60 ng g-1 fat), followed by hexachlorobenzene (HCB) (median: 14.31 ng g-1 fat), PCBs (median: 4.71 ng g-1 fat), and hexachlorocyclohexanes (HCHs) (median: 0.77 ng g-1 fat). DDT/DDE ratios across the samples vary between 0.09 to 32.24 and exhibit the hypothesis of sustaining illegal use of the banned pesticide. The historical or recent use of OCPs and possible emission sources of PCBs identified near studied farms may lead to increased levels of these contaminants in produced milk. The estimated daily intake (EDI) values were several orders of magnitude below the tolerable daily intake (TDI) fixed by FAO/WHO, though recorded concentration in some samples exceeded the maximum residue limits (MRLs) fixed by the EU, especially for OCPs. According to health risk assessments, consumption of raw milk did not pose an obvious cancer risk or other health problems for local inhabitants.

Hydrocarbons in the atmospheric gas phase of a coastal city in Tunisia: Levels, gas-particle partitioning, and health risk assessment.

Many studies have focused on aliphatic hydrocarbons and polycyclic aromatic hydrocarbons (AHs and PAHs) in different environmental compartments, especially atmospheric particles (aerosols), due to their adverse effects on the environment and human health. However, much less information is currently available on the content of AHs and PAHs in the atmospheric gas phase, which is a major reservoir of volatile and photoreactive compounds. Here, for the first time, we assessed the levels, gas-particle partitioning, human health risks and seasonal variations of AHs and PAHs in the atmospheric gas-phase of Bizerte city (Tunisia, North Africa) over a one-year period (March 2015-January 2016). Σ34PAH concentration in the gas phase over the period ranged from 6.7 to 90.6 ng m-3 and on average was 2.5 times higher in the cold season than in the warm season. Σ28AH concentration in the gas phase over the period ranged from 14.0 to 35.9 ng m-3, with no clear seasonal variations. In the gas phase, hydrocarbons were dominated by low-molecular-weight (LMW) compounds, i.e. 3- and 4-ring for PAHs and < n-C24 for AHs. Gas-phase concentrations of PAHs and AHs accounted for up to 80 % of the total (gas + particle phases) atmospheric concentrations of PAHs and AHs. Further analysis of gas-particle partitioning showed that LMW hydrocarbons preferential accumulated in the gas phase, and that gas-particle partitioning was not in equilibrium but dominated by absorption processes into the aerosol organic matter. Benzo[a]pyrene toxic equivalency quotient (BaP-TEQ) in the gas phase represented on average 37 % of the total atmospheric BaP-TEQ concentration, which was always higher in the cold season. Atmospheric gas is a significant factor in the risks of cancer associated with inhalation of ambient air. The Monte Carlo simulation-based exposure assessment model predicted that outdoor air exposure to PAHs does not pose a cancer risk to infants, but the children, adolescent, and adult populations may face a lower cancer risk during the warm season and a higher risk in the cold season.

Assessment of trace levels of aflatoxins AFB1 and AFB2 in non-dairy beverages by molecularly imprinted polymer based micro solid-phase extraction and liquid chromatography-tandem mass spectrometry.

A selective molecularly imprinted polymer (MIP) adsorbent was synthesised and used in a batch micro-solid phase extraction format for isolating aflatoxins (AFB1, and AFB2) from non-dairy beverages before liquid chromatography-tandem mass spectrometry determination. MIP synthesis (precipitation polymerization in 3 : 1 acetonitrile/toluene as a porogen) was performed with 5,7-dimethoxycoumarin (DMC), methacrylic acid (MAA) and divinylbenzene-80 (DVB) as a dummy template, functional monomer and cross-linker, respectively (1 : 4 : 20 molar ratio). 2,2'-Azobisisobutyronitrile (AIBN) was used as a polymerization initiator. The adsorbent MIP (50 mg) was enclosed in a cone-shaped polypropylene membrane (porous membrane protected molecularly imprinted micro-solid phase extraction), and parameters such as sample pH, mechanical (orbital-horizontal) shaking, the extraction time (loading stage), the composition of the eluting solution, and the desorption time were optimised. The highest extraction yields were obtained by using 5 mL of non-dairy beverages (pH adjusted at 6.0), and mechanical shaking (150 rpm) for 15 min. Elution was performed with 5 mL of an acetonitrile/formic acid (97.5 : 2.5) mixture under ultrasound (325 W, 35 kHz) for 15 min. After eluate evaporation to dryness and re-dissolution in 150 µL of the mobile phase, the pre-concentration factor of the method was 33.3, which yields limits of detection within the 0.085-0.207 µg L-1 range. In addition, the current proposal was shown to be an accurate and precise method through relative standard deviation of intraday and inter-day assays below 18% and analytical recoveries in the range of 91-104%. However, the method was found to suffer from matrix effects.

Levels and risk assessment of hydrocarbons and organochlorines in aerosols from a North African coastal city (Bizerte, Tunisia).

The aim of this study was to assess, for the first time, the concentrations, sources, dry deposition and human health risks of polycyclic aromatic hydrocarbons (PAHs), aliphatic hydrocarbons (AHs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in total suspended particle (TSP) samples collected in Bizerte city, Tunisia (North Africa), during one year (March 2015-January 2016). Concentrations of PAHs, AHs, PCBs and OCPs ranged 0.5-17.8 ng m-3, 6.7-126.5 ng m-3, 0.3-11 pg m-3 and 0.2-3.6 pg m-3, respectively, with higher levels of all contaminants measured in winter. A combined analysis revealed AHs originating from both biogenic and petrogenic sources, while diesel vehicle emissions were identified as dominant sources for PAHs. PCB potential sources included electronic, iron, cement, lubricant factories located within or outside Bizerte city. The dominant OCP congeners were p,p'-DDT and p,p'-DDE, reflecting a current or past use in agriculture. Health risk assessment showed that the lifetime excess cancer risk from exposure to airborne BaP was negligible in Bizerte, except in winter, where a potential risk to the local population may occur.

Organochlorine pesticides and polychlorinated biphenyls in human adipose tissue from northern Tunisia: Current extent of contamination and contributions of socio-demographic characteristics and dietary habits.

The aims of the present study were to investigate the current exposure levels of persistent organochlorine compounds (OCs) in adipose tissues intraoperatively collected from 40 patients over 20 years undergoing non-cancer-related surgery residing in Northern region of Tunisia (Bizerte), which constitutes an exemplary case, and examined association between levels of contamination and both socio-demographic characteristics and dietary habits. Concentration of hexachlorobenzene (HCB), hexachlorocyclohexane isomers (α-HCH, ß-HCH, γ-HCH and δ-HCH), dichlorodiphenyltrichloroethane isomers (p,p'-DDT and o,p'-DDT) and metabolites (p,p'-DDE, o,p'-DDE, p,p'-DDD and o,p'-DDD) and 12 polychlorinated biphenyls (PCBs) congeners were measured using capillary gas chromatography with electron capture detector. Overall, residue levels of OCs followed the decreasing order of DDTs > PCBs > HCB > HCHs. DDTs levels ranged from 74.49 to 1834.76ngg-1 lipid and contributing to more than 90% to the sum of organochlorine pesticides (OCPs). p,p'-DDE was the most abundant in all samples and the p,p'-DDT/p,p'-DDE ratio (range between 1.85% and 58.45%) suggesting recent and ongoing exposure to banned commercial DDT products. PCB concentrations varied from 29.27 to 322.58ngg-1 lipid and PCB-180, PCB-153 and PCB-138 were the dominant congeners accounting for 70% of total PCBs. We did not find significant correlations between OC exposure levels and sex, parity, habitat areas and smoking habits. In females, the adipose tissue concentrations of DDTs, HCB and PCB-118 were positively correlated with age. There was statistically significant relationship between body mass index (BMI) changes and the adipose tissue levels of HCB and HCHs. No association was found between OCPs levels and dietary factors. However, our study suggests that fish consumption may be an important contributor of PCBs adipose tissue content of PCBs in Tunisian people. The presented work is highly significant, being the first study pointing out the chronic exposure to OCs in Bizerte.

Methoxylated polybrominated diphenyl ethers (MeO-PBDE) in human milk from Bizerte, Tunisia.

Methoxylated polybrominated diphenyl ethers (MeO-PBDEs) were determined in 36 human milk samples collected in 2010 from healthy mothers living in Bizerte region from Tunisia. Gas chromatography coupled to mass spectrometry working with negative ion chemical ionization (GC-NCI-MS) was used to identify and quantify residue levels on a lipid basis of organo-brominated compounds. Among the 8 examined MeO-PBDE congeners 6-MeO-BDE-47, 2'-MeO-BDE-68, 4'-MeO-BDE-49 and 5'-MeO-BDE-100 were detected in human milk at different levels and frequencies. This is the first study reporting 5'-MeO-BDE-100 and 4'-MeO-BDE-49 levels in human milk samples. Levels of ∑MeO-PBDEs ranged from 0.23 to 4.70ngg(-)(1) lipid weight (lw) in the samples, with a mean and median value of 1.52 and 1.11ngg(-1)lw respectively. Concentrations of ∑MeO-PBDEs in human milk were negatively correlated with age of primapara mothers (p<0.05) and no age-dependency was observed for multipara mothers. Primapara mothers had higher levels of MeO-PBDEs than multipara mothers however no statistical significance was observed. A weak correlation between ∑PBDEs and ∑MeO-PBDEs was found but not between BDE-47 and its methoxylated analog 6-MeO-BDE-47, suggesting differences in exposure pathways for these contaminants in humans and further supporting the hypothesis that MeO-PBDEs were likely not only originated from PBDE precursors.

Concentrations of organochlorine pesticides and polychlorinated biphenyls in human serum and their relation with age, gender, and BMI for the general population of Bizerte, Tunisia.

Human serum samples (n = 113) from Bizerte, northern Tunisia, collected between 2011 and 2012 were analyzed for 8 organochlorine pesticides (OCPs) including p,p'-dichlorodiphenyltrichloroethane (DDT) and its metabolites, hexachlorobenzene (HCB), hexachlorocyclohexane isomers, dieldrin, and heptachlor and 12 polychlorinated biphenyls (PCBs) congeners. Concentrations of these residues in serum were determined by gas chromatography with electron capture detector and total cholesterol (CHOL) and triglycerides (TG) levels were evaluated by enzymatic colorimetric method. HCB, p,p'-DDE, PCB-138, PCB-153, and PCB-180, were the most abundant organochlorine compounds (OCs) detected in >95 % of the study subjects. The mean levels of p,p'-DDE and HCB in serum were 168.8 and 49.1 ng g(-1) lipid, respectively. The sum PCBs concentrations ranged from 37.5 to 284.6 ng g(-1) lipid in the samples, with mean and median value of 136.1 and 123.2 ng g(-1) lipid, respectively. The PCB profile consisted of persistent congeners, such as PCB-138, PCB-153, and PCB-180 which contributed for approximately 82.7 % to the ∑PCBs. Statistical analysis showed that most OCs correlated significantly with age, considering all samples together or with gender differentiation. The present study shows that the levels of p,p'-DDE and ∑DDTs were significantly higher in females than in males (p < 0.05), while PCBs levels were significantly higher in male (p < 0.05) than in females. No statistically significant association was found between body mass index and concentration of any organochlorine pesticide or PCB congeners 153, 138, 180, or ∑PCBs.

Distribution and ecological risk of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in surface sediments from the Bizerte lagoon, Tunisia.

Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were determined in 18 surface sediment samples collected from Bizerte lagoon, Tunisia. The total concentrations of ten PCBs (∑PCBs) and of four OCPs (∑OCPs) in the sediments from this area ranged from 0.8 to 14.6 ng g(-1) dw (average value, 3.9 ng g(-1) dw) and from 1.1 to 14.0 ng g(-1) dw (average value, 3.3 ng g(-1) dw), respectively. Among the OCPs, the range of concentrations of dichlorodiphenyltrichloroethane and its metabolites (DDTs) and hexachlorobenzene (HCB) were 0.3-11.5 ng g(-1) dw (1.9 ng g(-1) dw) and 0.6-2.5 ng g(-1) dw (1.4 ng g(-1) dw), respectively. Compositional analyses of the POPs indicated that PCB 153, 138 and 180 were the predominant congeners accounting for 60 % of the total PCBs. In addition, p,p'-DDT was found to be the dominant DDTs, demonstrating recent inputs in the environment. Compared with some other regions of the world, the Bizerte lagoon exhibited low levels of PCBs and moderate levels of HCB and DDTs. The high ratios ΣPCBs/ΣDDTs indicated predominant industrial versus agricultural activities in this area. According to the established guidelines for sediment quality, the risk of adverse biological effects from such levels of OCPs and PCBs, as recorded at most of the study sites, was insignificant. However, the higher concentrations in stations S1 and S3 could cause biological damage.

Time course of organochlorine pesticides and polychlorinated biphenyls in breast-feeding mothers throughout the first 10 months of lactation in Tunisia.

Organochorine (OCs) residues were measured in human breast milk samples from four Tunisian women. Month-mix samples composed of weekly collected breast milk samples were analyzed over the lactation period between 3 days after delivery and 10 months post-partum. The concentrations of dichlorodiphenytrichloroethane and its metabolites (DDTs), hexachlorobenzene (HCB), hexachlorocyclohexane isomers (HCHs), dieldrin, and 20 polychlorinated biphenyl congeners (PCBs) were determined by gas chromatography with electron capture detection. The variation of OC residue levels in human milk was investigated for each woman individually. The average p,p'-DDE and p,p'-DDT concentrations declined from 661- and 438-ng g(-1) fat basis at day 3 to 77- and 106-ng g(-1) fat basis after 8 months, respectively. No essential changes in HCB, HCHs, dieldrin, and total PCBs concentrations in human breast milk occurred over the lactation periods investigated; the concentrations remained either relatively constant or show no significant weak decrease.

Concentration of polychlorinated biphenyls and organochlorine pesticides in mullet (Mugil cephalus) and sea bass (Dicentrarchus labrax) from Bizerte Lagoon (Northern Tunisia).

Concentrations of polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs) were determined in two fish species, mullet (Mugil cephalus) and sea bass (Dicentrarchus labrax), collected from Bizerte Lagoon and the Mediterranean Sea. In all samples, PCBs were found in higher concentrations than OCPs. The highest concentrations of OCPs and PCBs were found in sea bass, and in Bizerte Lagoon. Concentrations of DDTs and PCBs detected in this study were generally comparable or slightly higher than those found in studies from other Mediterranean and non-Mediterranean regions subject to a high anthropogenic impact. ∑PCBs, ∑HCHs and HCB levels were negatively correlated with lipid content, while no such correlation was seen for ∑DDTs. A significant correlation between levels and length and between levels and weight existed only for ∑PCBs. The daily intake of PCBs and OCPs ingested by people living in Bizerte through the studied fish species was estimated and compared with those observed in other areas.

Organochlorine and organobromine compounds in a benthic fish (Solea solea) from Bizerte Lagoon (northern Tunisia): implications for human exposure.

Information on the occurrence of persistent organic pollutants (POPs) in fish from Tunisia is scarce. In this study, thirty one persistent organic pollutants including organochlorine pesticides (OCPs) (dichlorodihenyltrichloroethane and its metabolites (DDTs), hexachlorocyclohexanes (HCHs) and hexachlorobenzene (HCB)), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and methoxylated polybrominated diphenyl ethers (MeO-PBDEs) were determined in solea solea muscle, from Bizerte Lagoon (northern Tunisia) and from the Mediterranean Sea (reference area) (northern Mediterranean). In the Bizerte Lagoon, contaminant concentrations generally followed this order: PCBs>DDTs>PBDEs>MeO-PBDEs>HCB>HCHs; while in the Mediterranean Sea, pollutant concentration followed this order: MeO-PBDEs>PCBs>DDTs>PBDEs>HCB>HCHs. Mean levels of organochlorine compounds were 1018 and 380 ng g(-1) lipid weight (lw) in fish from Bizerte Lagoon and the Mediterranean Sea, respectively. Mean concentrations of organobromine compounds were 279 and 301 ng g(-1) lw in sole from Bizerte Lagoon and the Mediterranean Sea, respectively. Organohalogen concentrations in fish from Bizerte Lagoon were similar or slightly lower than those reported for other marine fish species from other locations around the world. PCB, HCH, HCB and PBDE levels were negatively correlated with lipid content, while no such correlation was seen for DDTs. Assessment based on several available guidelines suggested an insignificant human health risk for dietary intake of HCB, lindane and PBDEs associated with consumption of sole. However, the estimated lifetime cancer risk from dietary exposure to DDTs and PCBs is a potential concern.

Determination of chlorinated pesticides, polychlorinated biphenyls, and polybrominated diphenyl ethers in human milk from Bizerte (Tunisia) in 2010.

Thirty persistent organohalogen compounds including organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) were determined in breast milk samples (n=36) of primipara and multipara mothers from Bizerte in 2010. The analytical procedure involved the application of liquid-liquid extraction and gas chromatography with electron capture detector (GC-ECD) or mass spectrometry detector (GC-MS) for identification and quantification. Organohalogen compounds were found in all the analyzed samples, with predominance of p,p'-DDE, p,p'-DDT, p,p'-DDD, HCB and PCBs. The mean concentration of ∑DDTs in breast milk was 1163.9 ng g(-1) lipid wt. The ratio of p,p'-DDE/p,p'-DDT was low, suggesting that there is fresh intake of commercial DDT products in Bizerte. The mean levels of HCB and PCB were 286.8 and 331.2 ng g(-1) lipid wt respectively. These results were compared with the levels obtained in a previous study carried out in the same area in 2003. A general decrease of ∑DDTs levels and an increase of PCB levels were observed. Among the 10 PBDE congeners evaluated, BDE-28, BDE-47, BDE-99, BDE-66, BDE-138, BDE-100, BDE-154, BDE-153, and BDE-183 were detected in the analyzed samples at different frequency. The total PBDE concentrations ranged from 2.5 to 22.6 ng g(-1) lipid wt in the samples, with a mean and median value of 10.7 and 9.8 ng g(-1) lipid wt respectively. To our knowledge, this is the first data of PBDEs in Tunisian human milk. The present study shows that age and parity are factors influencing the levels of some organohalogen compounds in human milk.

Simultaneous analysis of polychlorinated biphenyls and organochlorine pesticides in water by headspace solid-phase microextraction with gas chromatography-tandem mass spectrometry.

Headspace solid-phase microextraction combined with gas chromatography-ion trap tandem mass spectrometry (HS-SPME-GC-ITMS-MS) method has been developed and studied for the simultaneous determination of 15 organochlorine pesticides (OCPs) and 20 polychlorinated biphenyls (PCBs) in aqueous samples. To perform the HS-SPME polydimethylsiloxane (PDMS) (7, 30 and 100 microm film thickness) and polydimethylsiloxane-divinylbenzene (PDMS-DVB) fibers were initially compared on the basis of their absorption capacities for the selected compounds, and PDMS 100 microm film thickness was selected to accomplish the rests of essays. The influence of various parameters on OCPs and PCBs extraction efficiency by HS-SPME was thoroughly studied using GC-electron capture detector (ECD). Parameters such as collision induced dissociation (CID) resonant excitation amplitude and RF storage level were optimized to increase specificity and sensibility for ITMS-MS analysis. The performance of proposed HS-SPME-GC-ITMS-MS methodology with respect to linearity, reproducibility and limit of detection (LOD) was evaluated by water spiked with target compounds. The linear range of most compounds was found to be between 0.01 and 1 ng mL(-1) and the limits of detection were between 0.4 and 26 pg mL(-1). The reproducibility of the method (n = 6), expressed as relative standard deviation (RSD), was between 5 and 21%. Finally, developed procedure was applied to determine selected OCPs and PCBs in river water samples in concentration below 0.1 ng mL(-1) can be easily carried out with ultra-selectivity and precision.