Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Dieldrin”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,495 records · Page 83Linked to original sources
PubMed1993

Impact of organochlorine pesticide residues and PCBs on otters (Lutra lutra) in eastern England.

A study of otter (Lutra lutra) populations and levels of organochlorine (OC) pesticide residues and PCBs in otter faeces (spraints) was made on rivers in East Anglia, England. Population and contaminant levels are compared against target values. It is thought that the native otter population was almost extirpated during the study period. The current population must derive largely, if not entirely, from captive-bred animals introduced since 1983. Its range has expanded little and population levels, measured as an index, were generally low. Concentrations of OC pesticides and PCBs were similar to those of lowland stretches of western rivers; however, samples had a smaller proportion of dieldrin and a greater proportion of PCBs. Overall 44% of samples had concentrations of contaminants exceeding the 'level of concern'. It is considered that contamination, especially by PCBs, remains a factor influencing otter populations, which may not be viable in East Anglia without repeated releases of captive-bred animals.

Animals↗
PubMed1994

Pesticide residue levels in Argentinian pasteurised milk.

Pasteurised milk--120 samples--was analysed (in Santa Fe City, Argentina) to determine organochlorinated pesticides. Almost all samples showed the presence of such residues; the compounds more frequently detected being: heptachlor and its epoxide (98%) and hexachlorocyclohexane .HCH. alpha and gamma isomers. Residues of aldrin and dieldrin; chlordane (alpha and gamma); endosulfan (I and II); DDT (o,p-DDT, p,p'-DDE, o,p-DDD, p,p'-DDD) as well as hexachlorocyclobenzene (HCB) were also found. Despite their presence high concentrations are sporadic, the mean values being less than FAO/OMS tolerance limits. Relations between maxima concentrations and seasons were not found.

Animals↗
PubMed1995

Presence of airborne contaminants in the wildlife of northern Québec.

As part of the environmental impact studies of the Great Whale and the Nottaway-Broadback-Rupert (NBR) hydroelectric projects, Hydro-Québec collected data on the occurrence and levels of several contaminants present in wildlife from both regions between 1989 and 1991. The analyses performed included metals (mercury, arsenic, selenium, cadmium, lead, nickel and copper), polychlorinated biphenyls (PCBs as arochlors or the sum of 20-40 congeners) and organochlorine pesticides such as hexachlorobenzene (HCB), DDT, DDE, hexachlorocyclohexane (HCH), chlordane, mirex and dieldrin. Species sampled included fish (freshwater and marine), birds (waterfowl, gull and ptarmigan), terrestrial mammals (marten, mink and hare) and marine mammals (freshwater and marine seals, belugas). Most laboratory analyses were carried out on both muscle and liver tissues, but some were conducted on other tissues as well: feathers, eggs and blubber. The results indicate that numerous airborne contaminants were present in the wildlife of both the Great Whale and the NBR study areas and that their level of contamination was similar to that of other northern environments. Total mercury in muscle was high in piscivorous fish, birds and mammals (terrestrial and marine). We observed significant levels of cadmium and lead in the livers of some herbivorous terrestrial animals, such as ptarmigans and hares. Among the organochlorine contaminants analyzed, levels of PCBs and DDE in piscivorous birds (mergansers and loons) and in marine mammals (seals and belugas) were high. For some contaminants, such as mercury, cadmium, lead, PCBs and DDE, the levels observed in some species or tissues could be considered worrisome with regard to public health, if those species or tissues constitute an important part of traditional native diets.

Air Pollutants↗
PubMed1995

Arctic air pollution and human health: what effects should be expected?

Persistent contaminants such as heavy metals and organochlorine compounds are transported from distant sources to the Arctic by oceanic and atmospheric currents. Natives inhabiting the Arctic can be exposed, because they exist at the highest trophic level of the arctic aquatic food chain, along which biomagnification of contaminants occurs. We reviewed the data available on heavy metal and organochlorine body burden in natives from different regions of Nunavik (northern Québec) and assessed the potential risk of health effects. In addition, we investigated the relationship between each contaminant plasma level and omega-3 fatty acid content of plasma phospholipid, a surrogate measure for aquatic food consumption. Cadmium exposure appears to be unrelated to the consumption of species from the aquatic food chain (r = 0.0004; P = 0.99), whereas PCBs and mercury were (r = 0.49 and 0.52, respectively; P < or = 0.0001). Mean blood mercury levels measured in northern Québec natives were below those associated with significant neurological disorders. Typical daily intakes of dioxin-like compounds, PCBs, DDE, and dieldrin were estimated from the mean concentration in milk fat and pharmacokinetic models. The calculated PCB intake (0.3 microgram/kg/day) exceeds the acceptable daily intake, with effects on reproduction and development being the most relevant to assess in future epidemiological studies.

Air Pollution↗
PubMed1996

Contamination by persistent chemicals in food chain and human health.

Persistent polluting chemicals are, by definition, substances which have long half-lives or disappearance rates in the environment, mainly due to their chemical stability, but often also caused by unfavourable conditions for environmental/biological mineralisation processes to take place. DDT, lindane, dieldrin, HCB, and PCB are well known examples of chemicals which can be found in various parts/compartments of the environment, and in living organisms including man. The early findings in 1950s and 1960s of the persistent chlorinated pesticides in birds and fish populations in North America and Europe were obviously the results of deliberate and extensive use of these chemicals in agriculture and industry. The findings were confirmed and substantiated by national and international monitoring programmes, and it became clear that many field observations of threatened species convincingly could be correlated to the increasing levels of contamination. Still more man-made chemicals have been drawn into the field of interests as widespread pollutants, and the geographical areas in which contamination takes place have become ever larger. The threat to groundwater resources from infiltration of pesticides into soils, and the alarming reports on contamination of mothers milk are to-day well-known examples. They are described from many parts of the world. Similarly, the food chain biomagnification of several pesticides and of PCB which were already described from Great Lakes region in North America in the 1960s and from the Baltic Sea area in Europe in the 1970s has since then been followed by identical observations in the Danube basin in Eastern Europe and in Indian provinces during the 1980s. Scientifically, we are to-day able to describe many of the fundamental processes, including environmental transport and transformation, as well as exposure, uptake and metabolic patterns for many of the persistent man-made chemicals. Accordingly, we are reasonably well informed of the most obvious cause-effect chains which govern the process of increasing pollution. We understand and can often for most of the chemicals predict the hazards of the environment as well as to man. In spite of this experience, and contrary to belief created by our scientific knowledge, the problem of contamination is still increasing. This includes the frequency of reported accidents and damages from all over the world. It is obvious, therefore, that the question becomes a matter of concern for the global society and a call for world-wide attention through international bodies develops into a matter of urgency.

Animals↗
PubMed1996

Organochlorine pesticide residues in bovine milk from Leon (Spain).

Residue levels of the organochlorine pesticides (alpha-HCH, lindane, heptachlor-epoxide, aldrin, endrin, dieldrin, o,p'-TDE, p,p'-TDE, p,p'-DDE and p,p'-DDT) were determined in raw bovine milk and compared with the maximum levels allowed by the European Union (EU) in these foods. The highest incidence percentage of the ten insecticides measured was for lindane, followed by alpha-HCH and aldrin. Moreover, the highest mean residue level was for alpha-HCH. None of the samples analyzed exceeded the maximum levels allowed by the EU.

Animals↗
PubMed1977

Fate of [14C]aldrin in crop rotation under outdoor conditions.

[14C]Aldrin was applied to soils (about 3kg/ha) in outdoor boxes at various locations (Germany, England, and United States), and crops were cultivated (maize, wheat, sugar beets, and potatoes). In the following year, crop rotation experiments were carried out in the same soils without retreatment; in addition, wheat was grown in soils retreated with [14C]aldrin (3.5 kg/ha). After the harvest of both years, the distribution of aldrin and major metabolites (dieldrin; photodieldrin; hydrophilic metabolites including dihydrochlordene dicarboxylic acid; an unidentified nonpolar compound X; and unextractable metabolites) was determined in plants, soils, and leaching water. Two further conversion products, photoaldrin and aldrin-trans-diol, occurred in trace amounts only in a few samples. Metabolic pathways for aldrin under outdoor conditions are presented. The distribution of radioactive residues in soils and plants as well as their quantitative chemical composition are discussed, and comparisons are made between the different experimental sites, the crops, the first and second year, and retreated and nonretreated samples. The quantitative results are compared to those of field trials.

Agriculture↗
PubMed1977

Comparative ecotoxicology of halogenated hydrocarbon residues.

The term ecotoxicology is adopted in the sense of a comparative and integrated study of the undesirable effects of trace contaminants on the range of fauna and flora of an "ecosystem" or of a defined part or unit thereof. The importance of population changes over long periods of time is stressed. Sources, usage, and global trends of representative halogenated hydrocarbon (HHC) residues which appear as trace contaminants of environment, food, and living organisms are briefly compared: industrial solvents and intermediates, chlorofluoromethanes as an atmospheric pollutant, methyl bromide as a food and soil residue, HCH (hexachlorobenzene) as a fungicide residue, DDT, lindane (gamma-hexachlorocyclohexane), and dieldrin as insecticide residues, and polychlorinated biphenyls (PCBs) as industrial contaminants. A simple mathematical approach to the problem of relating inputs, persistence, and steady-state residue levels is explained. Persistence and biodegradation of representative compounds are compared. Attention is drawn to the persistence of hexachlorobenzene, the p,p'-dichlorodiphenyl- and hexachlorocyclopentadiene-derived moities of HHC residues. Ecotoxicological effects and their implications are discussed comparatively under the indirect effects of atmospheric pollutants and direct and indirect effects of trace contaminants of soil and aquatic ecosystems. Some conclusions related to research and "impact monitoring" are drawn.

Atmosphere↗
PubMed1985

A comparison of physiological changes in carp, Cyprinus carpio, induced by several pollutants at sublethal concentrations. I. The dependency on exposure time.

Carp were exposed to 10 different pollutants at sublethal concentrations for 6, 24, or 72 hr. Blood, liver, and white muscle samples were taken after the exposure time together with samples of control handled fish. Serum concentrations of glucose, cortisol protein, and cholesterol were determined. Similarly, the liver and muscle glycogen contents were measured. The effects of the following pollutants were examined: aldrin (100 micrograms/liter), atrazine (100 micrograms/liter), DDT (50 micrograms/liter), dieldrin (20 micrograms/liter), endrin (2 micrograms/liter), hexachlorbenzene (100 micrograms/liter), lindane (100 micrograms/liter), methanol (1 ml/liter), 4-N-phenol (100 micrograms/liter), toluene (100 microliters/liter). The rises in serum glucose and cortisol were the most frequent changes occurring after exposure to the pollutants. A decline in plasma protein and cholesterol content was also often observed. Liver glycogen concentration increased first in most cases and was reduced after longer exposure. Muscle glycogen was affected differently, sometimes reduced by exposure to the pollutants. The experimental design allows for the gradual increase in toxicity of the pollutants used regarding the applied concentrations. Furthermore, the aim of the paper is to evaluate the tests for proof of toxicity of those chemicals. The determination of serum glucose and cortisol levels can be proposed as mostly useful. The clearest changes in all parameters were found after treatment with 100 micrograms/liter atrazine and 50 micrograms/liter DDT. When serum glucose and cortisol concentrations were quickly elevated, signs for exhaustion could be seen after 72 hr of exposure.

Animals↗
PubMed1979

Mutagenic action of a series of epoxides.

The mutagenicity of a series of 13 epoxide compounds was studied using a bacterial plate assay system. The histidine-dependent tester strains TA98 (for frameshift mutagens) and TA100 (for base-pair substitution mutagens) of Salmonella typhimurium were used. Mutagenicity was evaluated both with and without the additon of rat liver microsomal extract. Dieldrin, diglycidyl ether of bis phenol A and 3 of its homologues were not mutagenic. Allyl glycidyl ether, n-butyl glycidyl ether, vinly cyclohexene diepoxide, glycidol, glycidal-dehyde, diglycidyl ether, diepoxybutane and diglycidyl ether of substituted glycerine were mutagenic in the TA100 strain, causing reversion of the bacteria to histidine independence. Dose-reponse curves of the mutagenicity of the latter 4 compounds were obtained. On a molar basis, glycidaldehyde was about 20-50 times more potent in producing mutation that were the other 3 epoxides in the dose-response test. In general, the mutagenicity of the epoxides was not enhanced or diminished by the addition of microsomal extract.

Drug Evaluation, Preclinical↗
PubMed1983

Further mutagenicity studies on pesticides in bacterial reversion assay systems.

A total of 228 pesticides (88 insecticides, 60 fungicides, 62 herbicides, 12 plant-growth regulators, 3 metabolites and 3 other compounds) was tested for mutagenicity in bacterial reversion-assay systems with 5 strains (TA100, TA98, TA1535, TA1537 and TA1538) of Salmonella typhimurium and a strain (WP2 hcr) of Escherichia coli. 50 pesticides (25 insecticides, 20 fungicides, 3 herbicides, 1 plant-growth regulator and 1 other compound) were found to be mutagenic. 5 of them required metabolic activation (S9 mix) for their activities. Among various chemical groups, organic phosphates, halogenated alkanes and dithiocarbamates showed higher ratios of mutagens. Although 22 of the pesticides tested have been reported to be carcinogenic, 7 of them, i.e., captain, DBCP, EDB, EDC, ETU, HEH and nitrofen, were detected as mutagens in the present assay. Most of the other 15 non-mutagenic carcinogens were organochlorine pesticides such as alpha-BHC, chlorobenzilate, p,p'-DDT, dieldrin and quintozene.

Carcinogens↗
PubMed1986

A comparative study on selected chemical carcinogens for chromosome malsegregation, mitotic crossing-over and forward mutation induction in Aspergillus nidulans.

10 "false negative" chemical carcinogens, i.e. ineffective in bacterial mutagenicity assays, were thoroughly investigated for their genotoxic activity in the mould Aspergillus nidulans. Forward mutations (methionine suppressors), mitotic crossing-over and chromosome malsegregation were the end-points scored. Positive results were obtained in tests for the induction of mitotic segregation with benzene, ethylenethiourea and urethane, which increased the frequency of abnormal presumptive aneuploid colonies with euploid sectors showing whole chromosome segregation (i.e. non-disjunctional diploids and haploids). The same compounds were ineffective in increasing the frequency of mitotic crossing-over or forward mutations. The other chemical carcinogens investigated, namely acetamide, amitrole, dieldrin, heptachlor epoxide, nitrilotriacetic acid, p,p'-DDT and thiourea were ineffective both as inducers of forward mutations and mitotic segregation.

Aspergillus nidulans↗
PubMed1993

Inhibition of t-[35S]butylbicyclophosphorothionate binding by convulsant agents in primary cultures of cerebellar neurons.

The characteristics of the picrotoxinin binding site present on the gamma-aminobutyric acidA (GABAA) receptor were studied in neurons using primary cultures of cerebellar granule cells. The binding properties of these sites in intact cultured cells were compared with those measured in cultured cell membrane preparations. t-[35S]Butylbicyclophosphorothionate (TBPS) binding was performed in cultured rat cerebellar neurons grown for 13 days. Binding parameters (Kd and Bmax) were similar to those reported in the literature determined using brain membranes. However, equilibrium was reached faster when using intact cultured neurons. Convulsant compounds like picrotoxinin (PTX) and pentylenetetrazol (PTZ) competitively inhibited the binding of TBPS in this in vitro system. Convulsant organochlorine pesticides (gamma-hexachlorocyclohexane gamma-HCH or lindane and the cyclodienes aldrin, endrin, dieldrin and alpha-endosulfan) competitively inhibited [35S]TBPS binding in cerebellar neuronal cultures. Inhibitory affinity constant (Ki) values were in the nanomolar range, alpha-endosulfan and endrin being the most potent inhibitors corresponding to their high toxicity in mammals. Stereospecificity was also shown for HCH isomers, the non-convulsant isomers (alpha- and delta-HCH) being 15-30 times less potent in inhibiting [35S]TBPS binding than the convulsant gamma-HCH, while the beta-isomer was inactive.

Animals↗
PubMed1988

Organochlorine and heavy metal contamination in the eggs of the Spanish Imperial Eagle (Aquila (heliaca) adalberti) and accompanying changes in eggshell morphology and chemistry.

Eggs of the Spanish Imperial Eagle (Aquila (heliaca) adalberti) contained small amounts of heavy metals and organochlorine contaminants, including DDE, aldrin, dieldrin and HCHs, PCBs. Levels of organochlorine, except DDE, have decreased from 1972 to 1984. This paper reports how the structural and chemical characteristics of modern shells differ from those of older shells, unaffected by pesticides. Also, fertile and infertile recent eggs are compared. A 12.6% decrease in eggshell thickness has occurred in conjunction with a slight decrease in degree of crystallisation, but no significant changes have been found in other structural variables. The difference in chemical composition of the shell between modern and old eggs is both qualitative (presence of chlorine, potassium, magnesium and copper in recent shells) and quantitative (increase in the percentage of phosphorus and sulphur). The only clear differences between fertile and infertile eggs were a greater increase of phosphorus content and altered crystallisation in the latter. No clear relation between the amount of the mineral constituents of the shell and morphological alterations was established. The levels of contaminants in the contents seemed to be independent of the chemical alterations of the eggshell. The breeding parameters of the overall population showed no significant changes after the introduction of pesticides. However, eggshell changes have occurred in this species, which is one of the rarest birds of prey of the world, and some breeding individuals have sufficiently thin shells to suspect reduced reproductive success.

Journal Article↗
PubMed1989

Organochlorine contaminants in eggs of Common Terns from the Canadian Great Lakes, 1981.

To determine if contaminant levels in Common Terns had changed over the last decade, we collected and analyzed eggs from four nesting colonies on the three lower Great Lakes during 1981. DDE and PCBs were detected in every egg from the four colonies. Dieldrin, mirex and trans-nonachlor were detected in more than 45% of the eggs. Seven other organochlorine contaminants (DDD, DDT, hexachlorobenzene, oxychlordane, cis-chlordane, cis-nonachlor and toxaphene) were detected in less than 25% of the eggs. Eggs from the Lake Ontario colony were generally the most heavily contaminated. Comparisons of DDE and PCB data with earlier studies of Common Terns indicated that contaminant levels in eggs from the four sampled colonies, or nearby sites, have decreased by up to 80-90% from 1969-1973 to 1981. Interspecies comparisons showed that Common Tern eggs have lower organochlorine residue levels than eggs of Caspian Terns or Herring Gulls. Dietary variation and migratory status are possible explanations for the differences in residue levels among species. Eggshell thickness, log-PCBs, and log-DDE were not significantly intercorrelated. Elevated contaminant levels in the early 1970s might be at least partly responsible for the decline of the Great Lakes Common Tern population over the past decade. Stabilization of population numbers during the early 1980s suggests that organochlorine pollution levels have been reduced to a point where they are no longer an important factor in the population dynamics of this species on the Great Lakes.

Journal Article↗
PubMed1990

A survey of organochlorine pesticide residues in cheese samples from three Mexican regions.

Organochlorine pesticide residues were determined in cheese samples from three Mexican regions. All samples were found to be contaminated by these residues: p,p'-DDE was present in 100% of the samples. Other pesticides found with high frequencies were HCB, three of the BHC isomers, as well as heptachlor and its epoxide. Also found, although less frequently, were residues of p,p'-DDD, p,p'-DDT, aldrin, dieldrin and endrin. Samples from the region known as Comarca Lagunera had the highest number of pesticides per sample. The highest concentrations of residues were found in cheese samples from the Soconusco and the Comarca Lagunera regions.

Journal Article↗
PubMed1993

Accumulation of organochlorine contaminants in double-crested cormorants.

Cormorant eggs and lipid samples from juvenile Cormorants were analyzed for 14 organochlorine contaminants. Low concentrations (geometric mean < 0.05 microg/g) of hexachlorobenzene (HCB), lindane, oxy-chlordane, heptachlor epoxide, dieldrin, endrin, mirex, DDD and DDT in eggs primarily reflected the wintering-ground origin of organochlorine contaminants. Overall geometric mean concentrations of DDE and PCBs in Cormorant eggs were 3.90 and 2.22 microg/g egg respectively, and would not affect reproduction or eggshell thickness. Eggshells averaged 0.44 mm in thickness and no correlation (r2 = 0.17) with log-transformed DDE residues in Cormorant eggs was evident. Only DDE and PCBs were detected in lipid samples from 5- to 8-week-old Cormorants (geometric mean approximately 1.0 microg/g lipid for each compound). The PCB: DDE ratios in Cormorant lipid from some individual colonies were 2-3.5 times greater than the ratio in eggs from the same colony, suggesting an accumulation of PCBs related to local diet. Juvenile Cormorants might serve as regional indicators of chemical residue contamination in Alberta, and provide a temporal perspective on changes in contaminant burdens in aquatic ecosystems.

Journal Article↗
PubMed1994

Organochlorine pesticides and hexachlorobenzene in tissues of fish and invertebrates caught near a sewage outfall.

Concentrations of organochlorine pesticides and hexachlorobenzene (HCB) were determined in 16 fish, 1 mollusc and 1 crustacean species living near a cliff-face sewage outfall. For the 15 organochlorine compounds scanned, HCB, chlordane, dieldrin and SigmaDDT were recorded in highest concentrations. There was considerable variation in concentrations between muscle and liver and between species. Livers had higher concentrations of organochlorines and a higher percentage lipid than muscle. The highest concentrations were recorded in livers of the elasmobranch and tetraodontiform fishes. Organochlorines were only recorded at low concentrations in muscle, often at or near detection limits. No organochlorines were detected in the two invertebrate species.

Journal Article↗