Chloroorganic chemicals emitted from the pulp and paper mill at Nekoski in central Finland were monitored for several years. Concentration time series are used for evaluating the environmental fate and the applicability and validity of an exposure models. Fitted elimination rates of 3,4,5-Tri-, 4,5,6-Tri-, Tetrachloroguaiacol and 2,4,6-Trichlorophenol are approx. 0.22 per day, or rather the half-lives are approx. 3 days. The elimination is most likely by biodegradation and transport-controlled. For 2,3,6-trichloro-p-cymene, fate simulations indicate significant volatilization and sedimentation. Good agreement is achieved with a one-dimensional steady-state box model, except for concentrations in fish. For a reliable assessment of environmental damage, laboratory experiments, monitoring and simulations need to be in tune.

The monitoring the content of organochlorine insecticides and polychlorinated biphenyls in heterogeneous system of water-sediment is of a primary interest for the researching of contamination of the aquatic ecosystem because of high bioconcentration factors of these compounds and their bioaccumulation in flora and fauna of the aquatic basin. The sampling of water and sediment were done in the Boka Kotorska Bay (south Adriatic Montenegro Seaside), and estuary Bojana - Ulcinj, Montenegro (Yugoslavia), in AuTumn of 1995. The residues of organochlorine insecticides and polychlorinated biphenyls were determined by gas chromatography, Varian 3400 with capillary columns OV-101, length 25 m, with ECD. The residues of isomers of HCH (hexachlorocyclohexane), DDT and PCB (polychlorinated biphenyls) were identified in all investigated samples.

Information on exposure levels to organochlorine compounds (OCs) in child population is limited, despite their greater vulnerability to the adverse health effects of these chemicals.To determine serum concentrations of 10 OCs (including organochlorine pesticides and polychlorinated biphenyls –PCBs–) in children living in agricultural communities from Almería (South-Eastern Spain), and to identify the main predictors of exposure related to socio-economic characteristics, diet and lifestyle.A cross-sectional study was conducted on 133 children aged 6–11 years selected from public schools of the study area. OCs compounds were determined in serum samples by GC/ECD. Anthropometric measures were obtained during sample collection. Information on sociodemographic characteristics, parental occupation, residential history, lifestyle and frequency of food consumption, among other relevant factors, was obtained by questionnaires administered to the mothers.Geometric means of serum concentrations (ng/ml) were 0.11 for β-hexachloro-cyclohexane (β-HCH), 0.09 for endosulfan, 0.20 for endosulfan-ether, 0.51 for hexachorobenzene (HCB), 0.08 for mirex, 0.06 for oxychlordane, 0.36 for p,p'-DDE, 0.20 for PCB 138, 0.36 for PCB 153, and 0.45 for PCB 180. Percentage of samples above the limit of detection (0.05 ppb) ranged from 32 (β-HCH) to 100 (HCB). A high variability in OC levels depending on the compound was observed between our results and others found in similar studies carried out in children. Variables related to fish consumption were found to be the major dietary determinant of PCB 138, p,p´-DDE, endosulfan-α, β-HCH, mirex and oxychlordane levels.Children participating in this study showed detectable levels of many OC, despite these compounds are no longer used. Their presence in children serum can be explained by their high lipophilicity and environmental persistence, leading to contamination of fatty food. In this line, fish consumption seemed to be the most relevant determinant of OC levels found in our study.

Hepatic mRNA levels of the dio2 gene (deiodinase 2), implicated in thyroid hormone homeostasis, were analyzed in trout from six remote lakes in the Pyrenees (Spain) and the Tatra Mountains (Slovakia). Highest levels corresponded to fish from the two coldest lakes in Pyrenees, whereas relatively low levels were found in the Tatra lakes. These values correlated with the presence of highly-brominated polybrominated diphenyl ethers (PBDE) congeners in the muscle of the same animals, reflecting the distribution of these compounds across European mountain ranges. In contrast, cyp1a expression levels, diagnostic for the presence of dioxin-like pollutants, mirrored the distribution of semi-volatile organochlorine compounds, indicating the specificity of the two types of biological responses. Exposure to PDBEs is known to increase transcription of dio2 and other thyroid-related genes in laboratory experiments; we propose that our data reflects the same phenomenon in natural populations, driven by anthropogenic pollutants at the environmental concentrations.

Research on hexachlorobutadiene (HCBD) has increased since its listing in the Stockholm Convention on Persistent Organic Pollutants in 2011. However, thorough reports on recent data regarding this topic are lacking. Moreover, potential associations between HCBD and some chlorinated organics have usually been ignored in previous research. In this review, possible formation pathways and sources, current environmental occurrences and human exposure risks of HCBD are discussed, as well as the association with several organochlorine compounds. The results reveal that unintentional production and emission from industrial activities and waste treatments are the main sources of HCBD. Similar precursors are found for HCBD and chlorobenzenes, indicating the presence of common sources. Although recent data indicates that levels of HCBD in the environment are generally low, risks from human exposure to HCBD, together with other pollutants, may be high. More attention in the future needs to be paid to the mixed contamination of HCBD and other pollutants from common sources.