Environmental Toxicology

In 1962, what was then a landmark novel ‘Silent Spring’ was published, the author was Rachel Carson. The novel highlighted the effects of man made chemicals on the environment and ecosystems. Carson describes in this novel, the powerful and detrimental effects that humans have on the natural world
This report will describe the harmful effects of environmental chemicals on man and ecosystems and attempts to assess whether these effects have lessened since the publication of Rachel Carson’s ‘Silent Spring’. Scientific evidence will be presented of the changing effects of environmental chemicals through time and on a global scale. Their methods of toxicity will be described

The Niagara Falls speak to us with great clarity about the evolution of the relationship between man and nature in Western culture. Here a shift can be recognized both in aesthetic and physical terms – from feelings of repulsion and anxiety to ones of enchantment and delight, from the fear of the overwhelming power of the falling waters to the illusion of man’s total control of them. Paradoxically, the Niagara region, a key node of the Great Lakes ecological and economic system, is a region that did not lack planning: the construction of the western end of the Erie Canal, the system of parks designed by Olmsted and Vaux in both Niagara Falls and Buffalo, and the large infrastructures Robert Moses and his Power Authority built in Niagara County, not to mention all of the utopian urban projects that were developed for Grand Island and Niagara Falls. Yet today Niagara is one of the poorest and most socially devastated counties in the state of New York. Its once booming industry has nearly completely evaporated, hiding a territory riddled with toxic landfills and decrepit neighbourhoods behind the touristy curtain of the falls. So what went wrong? How did the grandeur of the past get lost?

Recently, a novel approach to a highly sensitive and quantitative detection of rare earth element (REE) ions including La3+, Eu3+ and Tb3+, by the polymerase chain reaction (PCR) technique, has been reported. The detection of REE ions is based on the catalytic nature of REE ions targeting the deoxyribonucleic acid (DNA), thus monitoring of the ions can be achieved by reading the level of intact DNA by PCR. Despite of its high sensitivity (at ppb to ppt levels), the conventional PCR-based REE detection protocol requires certain length of time (1-2 hours). In the present study, we modified the PCR-based REE detection protocols by employing the high-speed PCR, and performed the automated and rapid detection of La3+ in small-sized aqueous samples within 5min.

Cadmium(Cd) is one of the most dangerous occupational and environmental toxins. The objective of the present
study is to examine the potential prophylactic effects of phytic acid (PA) on thyroid hormones of male rats
intoxicated with Cd. The male albino rats were divided into five groups: group I (control) was fed with the basal
diet, group II was intoxicated with Cd in drinking water, groups III, IV, and V were intoxicated with Cd in drinking
water and fed with the diet containing 3.5, 7, and 10 g of PA/kg, respectively. The results indicated that the serum
calcium, iron (Fe), and total Fe binding capacity levels and serum T3 and T4 in Cd-treated rats of group II were
decreased when compared with the control group, while PA-administered groups with Cd showed a significant
improvement when compared with the Cd-treated rats only. Serumthyroid stimulating hormone (TSH) level was
significantly increased in Cd-treated rats compared with the control group, while the addition of PA in diet
decreased the high levels of TSH. These results indicated a prophylactic effect of PA against Cd-induced toxicity
in rats.
Keywords
Cadmium, phytic acid, thyroid, T3, T4, TSH, toxicity

Perfluorooctanoic acid (PFOA) is a widespread contaminant in
the environment, that is, implicated in several toxicities. The
intestinal wall is first surface of interaction with any toxicant
after exposure through the oral route. Previous studies have
demonstrated: increased intestinal bioaccumulation of
PFOA in different experimental animals, PFOA-induced
changes in DNA methylation of several tissues, and alterations
in expression of tight junction (TJ) genes due to epigenetics
changes. Nevertheless, evidence on the toxicity of
PFOA on intestinal epigenetics and TJ genes is limited.
Thus, the present work investigates PFOA-induced changes
in expression of epigenetic genes of the colon in relation to
TJ genes alterations. CD-1 mice were orally dosed with 4
different concentrations of PFOA (1, 5, 10, or 20 mg/kg/d)
for 10 consecutive days, and its bioaccumulation and
induced changes in the expression of TJ and epigenetic
genes in the colon were investigated. The PFOA was accumulated
in very high concentrations in the colon tissue and
decreased the expression levels of DNA methyltransferase
genes (Dnmt3a and DNMT3b). However, no significant
alterations were observed in expression levels of 10-11
translocation (TET1 and TET2) genes. We also found a
significant reduction in the mRNA expression of TJ
protein-1 (TJP1) at the highest concentration of PFOA.
Furthermore, the mRNA expression levels were significantly
increased for occludin (OCLN) and Claudins
(CLDN2, CLDN3, CLDN8) genes at higher concentrations.
Therefore, our study demonstrates that PFOA initiates
DNA methylation alterations and changes the expression
of genes necessary for preserving the integrity of the colon
barrier.

Manganese (Mn) is an essential nutrient, though exposure to high concentrations may result in neurotoxicity characterized by alterations in dopamine neurobiology. To date, it remains elusive how and why Mn targets dopaminergic neurons although recently the role of the dopamine transporter has been suggested. Our primary goal of this study was to examine the potential roles of the monoamine transporters, dopamine transporter (DAT), serotonin transporter (SERT) and norepinephrine transporter (NET), in neuronal Mn transport. Using striatal synaptosomes, we found that only inhibition of DAT significantly decreased Mn accumulation. Furthermore, weanling rats chronically exposed to Mn, significantly accumulated Mn in several brain regions. However, rats receiving the specific DAT inhibitor GBR12909 (1 mg/kg bw, three times/week; four weeks) had significantly lower Mn levels only in the globus pallidus compared to saline-treated rats (p<0.05). Our data show that inhibition of DAT exclusively inhibits Mn accumulation in the globus pallidus during chronic exposure.

Exposure to particulate matter (PM) may alter lung homeostasis inducing changes in fluid balance and host defense. Bioavailability of soluble PM compounds like polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and transition metals has been shown to play a key role in lung injury. We have previously characterized the size, shape, and chemical components of urban air particles from Buenos Aires (UAP-BA) and their biological impact on lungs. Herein, we evaluate the possible toxic effect of UAP-BA-soluble fraction (UAP-BAsf) on pulmonary cells obtained from young (1-2 months old) and aged (9-12 months old) Wistar rats using phagocytosis, oxidant-antioxidant generation, and apoptosis as endpoints. UAP-BA were collected in downtown BA and residual oil fly ash (ROFA), employed as a positive control, was collected from Boston Edison Co., Mystic Power Plant, Mystic, CT, USA. Both particle-soluble fractions (sf) were employed at concentrations ranging from 0 to 100 m...

Hexavalent chromium is the major terrestrial pollutant released from electroplating industries, tanneries, thermal power plants and sewage. Cr(VI) is reported genotoxicant in vertebrates. Sub-lethal level of Cr(VI) can cause DNA damage. Earthworms are ecologically important soil invertebrates, used for ecotoxicological studies. In present study coelomocytes of Dichogaster curgensis were used for assessing Cr(VI) genotoxicity using single cell gel electrophoresis [(SCGE) i.e. comet assay] following in vitro and in vivo exposures. Cr(VI) produces reactive oxygen species (ROS) in the cellular system, which can be a major cause of DNA damage. Dose dependent DNA damage was observed during in vitro exposure, while in vivo exposure showed increasing DNA damage till 30 ppm in terms of arbitrary units and unexpected decrease in arbitrary units at 70 and 100 ppm of Cr(VI). It is speculated that the decrease in arbitrary units at higher concentrations might be due to lower DNA mobility, caused by formation of different types of cross-links.

The clays consumed by geophagous individuals contain large quantities of aluminum, a known neurological and hematological toxin. This is the first study to evaluate the risk of aluminum poisoning in geophagous individuals. Blind determinations of plasma and urinary aluminum concentrations were carried out in 98 anemic geophagous pregnant women and 85 non-anemic non-geophagous pregnant women. Aluminum concentrations were significantly higher (P < 0.0001) in the geophagous anemic women than in the controls, with odds ratios of 6.83 (95% confidence interval [CI] = 2.72-19.31) for plasma concentrations (13.92 ± 14.09 μg/L versus 4.95 ± 7.11 μg/L) and 5.44 (95% CI = 2.17-14.8) for urinary concentrations (92.83 ± 251.21 μg/L versus 12.11 ± 23 μg/L). The ingested clay is the most likely source of this overexposure to aluminum. If confirmed, the clinical consequences of this absorption for pregnant women and their offspring should be explored.

The influence of water hardness and dissolved organic matter (DOM) on bioavailability of organic chemicals to Daphnia magna was studied by using benzo[a]pyrene (BaP), pyrene, atrazine, and 3,3Ј,4,4Ј-tetrachlorobiphenyl (TCB) as model compounds. Two types of DOM were used, namely Lake Kontiolampi, Joensuu, Finland water (KL) and Nordic reference fulvic acid (NoFA) dissolved in artificial freshwater. Binding of the four contaminants by KL DOM decreased with increasing water hardness. Furthermore, increasing hardness reduced the binding of BaP and pyrene to NoFA. The binding of atrazine and TCB by NoFA was low and was not significantly affected by water hardness. In the DOM-free samples, the bioconcentration of the four contaminants in D. magna usually was not affected by water hardness. In the presence of DOM, the bioconcentration factors (BCFs) were lower (except for atrazine) than in the DOM-free controls. In the presence of both types of DOM, increasing water hardness resulted in higher BCFs for BaP. The bioconcentration of pyrene and TCB increased with increasing water hardness in the presence of KL DOM. In conclusion, the effects of DOM and water hardness on bioavailability of hydrophobic chemicals depend on the type of chemical and on the properties of DOM.

Concentrations of arsenic, cadmium, copper, lead, and nickel were measured in soils, house mice (Mus musculus), and the main food items of this omnivorous mouse to examine the occurrence of these metals in selected components of a seasonal wetland. Soil concentrations of copper, lead, and (in some areas) nickel were elevated, but extractable soil concentrations indicated low bioavailability of metals. Levels of most metals in mice and composited arthropods were consistent with reference site concentrations from other studies. However, copper was found to be particularly mobile within the local ecosystem and accumulated in house mouse carcasses and composited arthropods at substantial levels. Metal residues in Scirpus robustus (alkali bulrush) roots exceeded those in seeds, consistent with patterns of bioaccumulation commonly observed in plants. Uptake and bioaccumulation factors for S. robustus seeds and roots, arthropods, and mouse carcasses and livers are reported. Concentrations of lead and nickel in S. robustus roots exhibited significant linear relationships with levels in soils. Copper levels in S. robustus seeds varied significantly with those in house mouse livers, suggesting that trophic transfer of copper from this food source to mice occurred. However, other spatial patterns of bioaccumulation in S. robustus and house mice relative to soil/seed concentrations were absent. Metal levels in house mice bore no relation to body weight or estimated age.

Dissolved hydrophobic chemicals can be concentrated with a passive, in situ concentration-extraction sampler (PISCES), an inexpensive and easy-to-use device made from plumbing parts and polyethylene film. PISCES is intended to mimic the direct uptake of chemicals from water by fish without the complications of metabolism and the uncertainty of location of exposure. This report examines the practical application of PISCES to a problem in identifying the source of PCBs to the Black River (NY). PISCES were deployed on three occasions at stations throughout the length of the river. Solvent recovered from the PISCES was analyzed for polychlorinated biphenyl (PCB) congeners. Relative homolog abundances and absolute amount of recovered PCBs pointed to a particular river reach as a possible source. A fourth set of samples taken in the city of Carthage (NY) defined a plausible source. Conventional sampling methods would not have been effective in this situation.

The purpose of this study was to discuss the effect of the chemical structure of anionic and non-ionic surfactants and surface activity on toxicity. Single and binary mixtures of three ether carboxylic derivative surfactants and three amine-oxide-based non-ionic surfactants were used. Toxicity was determined using three test organisms: freshwater crustaceans (Daphnia magna), luminescent bacteria (Vibrio fischeri), and microalgae (Selenastrum capricornutum). The toxicity of surfactants is related to the hydrophobic alkyl chain, the degree of ethoxylation, and the critical micelle concentration of surfactants. Relationships found agreed with the fact that the lower toxicity is shown by the shorter alkyl chain. There is a strong relation between surface activity and toxicity: the toxicity increased as the CMC of the surfactant or mixtures of surfactants decreased. Commercial products are formulated using surfactants mixtures, so it is important to know their behavior using an easily measured property: the least toxic mixtures were formed by the surfactants having lower individual toxicity. Around the CMC, our data show a synergism for the binary mixtures. The results have given rise to a classification of the different surfactants and their mixtures according to the organism test, as safe, harmful or toxic. V. fischeri was in general the most sensitive microorganism to the toxic effect of the surfactants, followed by Daphnia magna, while Selenastrum capricornutum was more tolerant. These results can be useful for selecting technically efficient surfactants and their mixtures with a lower ecotoxicity on the aquatic environment.

In order to determine the impact of nitrogen deficiency in medium, growth rate and carotenoids contents were followed during 15 days in two strain Dunaliella spp. (DUN2 and DUN3), isolated respectively from Azla and Idao Iaaza saltworks in the Essaouira region (Morocco). These microalgae were incubated at 25 ± 1 °C with a salinity of 35‰ and continuous light in four growth media with different concentrations of sodium nitrate (NaNO 3): 18.75 g/L, 2.5 g/L, 37.5 g/L and 75 g/L. Maximum of cell density was observed under high sodium nitrate concentration during logarithmic phase of growth. The highest specific growth rate was 0.450 × 10 6 ± 0.006 cells/mL and 2.680 × 10 6 ± 0.216 cells/mL, respectively for DUN2 and DUN3. Carotenoids production mean were not stimulated under nitrogen deficiency, and the highest content was showed in DUN2 at high nitrogen concentration (3.210 ± 0.261 μg•mL-1) compared with DUN3 strain.

This study was conducted for assessment of human health risks due to intake of heavy metal cont aminated vegetables through determination of the heavy metals' concentrations in soil and vegetables grown on it nearby Buriganga River, Dhaka, Bangladesh. Flame Atomi c Absorption Spectroscopy (AAS) was used to determine the concentrations of heavy metals. Moreover, Health Risk Index (HRI) of heavy metals was also calculated. The mean concentrations of heavy metals in soil were found in the decreasing order of Fe>Cr>Zn> Ni>Cu>Pb>Cd but in the case of roots and edible parts of vegetables, the mean concentrations of different heavy metals were as decreasing order of Fe>Cr>Zn>Pd>Ni>Cd>Cu and Fe>Cr>Zn>Pd>Ni>Cu>Cd respectively. In case of roots and edible parts of vegetables, except Cu and Ni all other heavy metal concentrations were higher than permissible limit. The HRI values of Cd, Cr, Fe, Pb and Zn were greater than 1 which indicated that contaminated vegetables were awfully detrimental to human health. Therefore, soil contamination as well as the heavy metal uptake into human body should be preven ted to avoid the health risk caused by heavy metal.

A variety of chemicals including foaming agents are used to aid in the protection of forest resources from the wild land fires. The fire-fighting foams (FFFs) are formulations composed principally of surfactants. As a part of Japanese national project, environmentally inert FFFs have been developed. There is an emerging need for testing the impacts of these FFFs on the living organisms composing the typical landscapes or ecosystems in Japan. In the present report, we aimed to describe our latest attempt for assessing both the short-tem and long-term impacts of FFFs in aquatic (fresh water) and semi-aquatic (wetland) ecosystems , by employing the laboratory-sized model assays (preliminary studies) and the biotope-based observation, respectively. In the biotope assays which was based on the observation in compact biotopes mimicking the fresh water environments and wetland, both the acute and long-term eco-toxic impacts of two FFFs (soap-based and synthetic detergent-based) were assessed. Spraying of synthetic detergent-based foam formula was shown to be more toxic compared to soap-based formula and mock water treatment.

Chromium(III) oxide (Cr 2 O 3 ) is used for industrial applications such as catalysts and pigments. In the classical form, namely the fine particle, Cr 2 O 3 is insoluble and chemically stable. It is classified as a low-toxicity chromium compound. Recently, industrial application of nanoparticles (a new form composed of small particles with a diameter of 100 nm, in at least one dimension) has been increasing. Cellular effects induced by Cr 2 O 3 nanoparticles are not known. To shed light upon this, the release of soluble chromium from Cr 2 O 3 nano-and fine-particles in culture medium was compared. Fine Cr 2 O 3 particles were insoluble in the culture medium; on the contrary, Cr 2 O 3 nanoparticles released soluble hexavalent chromium into the culture medium. Cr 2 O 3 nanoparticles showed severe cytotoxicity. The effect of Cr 2 O 3 nanoparticles on cell viability was higher than that of fine particles. Cr 2 O 3 nanoparticles showed cytotoxicity equal to that of hexavalent chromium (K 2 Cr 2 O 7 ). Human lung carcinoma A549 cells and human keratinocyte HaCaT cells showed an increase in intracellular reactive oxygen species (ROS) level and activation of antioxidant defense systems on exposure to Cr 2 O 3 nanoparticles. Exposure of Cr 2 O 3 nanoparticles led to caspase-3 activation, showing that the decrease in cell viability by exposure to Cr 2 O 3 nanoparticles was caused by apoptosis. Cellular responses were stronger in the Cr 2 O 3 nanoparticles-exposed cells than in fine Cr 2 O 3 -and CrCl 3 -exposed cells. Cellular uptake of Cr 2 O 3 particles were observed in nano-and fine-particles. The cellular influence of the extracellular soluble trivalent chromium was lower than that of Cr 2 O 3 nanoparticles. Cr 2 O 3 nanoparticles showed cytotoxicity by hexavalent chromium released at outside and inside of cells. The cellular influences of Cr 2 O 3 nanoparticles matched those of hexavalent chromium. In conclusion, Cr 2 O 3 nanoparticles have a high cytotoxic potential. # 2011 Wiley Periodicals, Inc. Environ Toxicol 00: 000-000, 2011.

In the study, first-time personal exposure level of polycyclic aromatic hydrocarbons (PAHs) was measured during cooking hours in participants of three different types of kitchen both in the particulate and gaseous phase using traditional and improved cookstoves. Along with that, indoor particulate matter (PM) concentration was also estimated during the cooking hours to examine the impact of intervention in different kitchens. The results of the study clearly revealed that the kitchen characteristics and type of cookstove technology have a significant impact on PM 2.5 , PM 1 and PAHs concentration. Cookstoves intervention has resulted in maximum reduction of PM 1 i.e. 75% in an enclosed kitchen followed by semi-enclosed and open kitchen having 71% and 52%, respectively. In addition, correlation analysis of PM 2.5 and PM 1 with PAHs showed a strong association (r 2 = 0.9), showing the affinity of PAHs to bind to fine range of particles. Health risk assessment was also carried out to assess the PM daily dose and carcinogenic and non-carcinogenic risk due to inhalation of PAHs. The study confirmed the personal concentration of PAHs compounds was significantly high (p < 0.05) during use of traditional cook-stove compared to improved cookstove among all the three kitchens. Furthermore, to measure the toxicity levels, PAHs concentrations have been converted to benzo[a]pyrene equivalence for calculating cancer and non-cancer effects using toxicity equivalency factors. The overall lifetime carcinogenic risk was the highest 2.5E-03, 6.4E-04 among women who prepared meals in the enclosed kitchen compared to 8.4E-04, 1.3E-04 in semi-enclosed and 2.2E-04, 4.6E-05 in the open kitchen during use of traditional and improved cookstoves, respectively, which exceeded the US EPA standard i.e. 1 × 10 −6. The study underlined the importance of personal monitoring for exposure, and risks-based studies along with the time-activity of user to measure the actual inhalation risk for the participants. These findings indicated that women are exposed to hazardous smoke in the indoor kitchen and are at greater risk of developing cancer, especially in rural areas.

In this research article the arsenic contents was determined using HGAAS. The water and blood samples were collected from Ballia region, the samples were prepared for testing with the help of HGAAS. Arsenic in drinking water is the major cause of Arsenic toxicity. Most of the reports highlighted chronic Arsenic toxicity in man increases. In contrast inorganic arsenic compound are known human carcinogens, based on sufficient evidence of carcinogenicity in human. From view point of health gastrointestinal effects, anemia, peripheral neuropathy, skin lesions, hyper pigmentation, and liver or kidney damage in humans. Inorganic arsenic exposure in Human. By the inhalation has been shown to be strongly associated with lung cancer, while ingestion of inorganic arsenic in humans has been linked to a form of skin cancer and also to bladder, liver, and lung cancer. Hydride generation atomic absorption spectrometry (HGAAS) is highly specific technique, which is widely used for trace metal analysis, This HGAAS is stable, easy to operate and produces sufficient atomization to enable good sensitivity and freedom from much inter element interference is a very valid option for elemental analysis, with the help of this technique, it can be analyzed.

Natural toxins from plant sources with wide ranges of biological activities reflect the upswing of drug design in the pharmaceutical industry. Rubia cordifolia L. is one of the most important red dye yielding plants. Most of the former researches have focused on the bioactive compounds from the roots of R. cordifolia, while no attention was paid towards the fruits. For the first time, here we report the presence of dibutyl phthalate in the fruits of R. cordifolia. Structural characterization was carried out using Ultraviolet-Visible spectrophotometer (UV-Vis), Fourier transform infrared (FTIR), gas chromatographymass spectrophotometer (GC-MS), Nuclear magnetic resonance (NMR). Acute toxicity of the crude ethanolic extracts of the R. cordifolia fruits was examined in Swiss albino mice. No mortality was observed in all treated mice with 100, 500, 1000 mg/kg body weight of crude extract of R. cordifolia fruit and it indicates that the LD 50 value is higher than 1000 mg/kg body weight. This study exhibited a significant change in the body weight. Alanine transaminase (ALT), total protein, triglycerides, glucose, and also the histopathological analysis of liver for all treated mice showed difference from the control group. The dibutyl phthalate was further evaluated for the toxicity study through in silico analysis. Together, the results highlighted that the toxic potential of R. cordifolia fruits extracts and also the toxicity profile of the fruit should be essential for the future studies dealing with the long term effect in animals. V C 2015 Wiley Periodicals, Inc. Environ Toxicol 00: 000-000, 2015.

Fungal pigments are a potential resource as natural food colorant. Endophytic fungus SX01, which is able to produce abundant soluble red pigments, was isolated from the twigs of Ginkgo biloba L. For further research and utilization of this strain and its secondary metabolites, morphological and molecular characteristics of SX01 was identified. Morphological identification which employed light microscope and scanning electron microscope showed that SX01 was a species of genera Penicillium. ITS1-5.8S-ITS2 region and 18S rRNA gene were then cloned, and the molecular phylogeny of these two sequences proved that strain SX01 was Penicillium purpurogenum.

Tannery waste waters decrease the quality of water bodies into which they are discharged is of large scale environmental concern. Disposition of tanning effluents e.g. Chromium (Cr) into the environment creates inauspicious outcomes by modifying the normal physiochemical properties of soil and water. It is determined that Chromium is the principal threat whenever tanning industry derives in to practice. Cr is extremely venomous and carcinogenic to humankind, animals, vegetations and as well overall environment. The paper was executed solely on secondary information by conferring literature informants including scientific journals, conference articles document and internet site that focused on the effects of tannery waste water and assessment of alternative treatment options used to reduce, removal, retrieve or reprocess Cr from the waste water. Effective management of tannery effluent is the need of the hour. Although a lot of treatment alternatives were assessed to preclude its effect on the environment, neither of them forced out Cr completely. In some cases researchers however successful enough practicing biotechnological methods to reduce the strength and fatal state of Chromium (e.g., Cr(Vl)). Hence, treatment alternatives are either; complex, energy consuming, expensive or applicable to a indisputable portions of the world due to engineering science or proficient work force requirement. Consequently, to tackle these important challenge demanding environmental ordinance with jurisprudence implementation has to be practiced to apply improve treatment scheme which is widely applicatory. Defilers must acknowledge the environmental cost of their manufacture and treated according to polluter pay or precaution precepts. Furthermore, the general public has to be aware of it and all concerned organizations and authorities have to work hard to accomplish zero discharge level or leastwise to gain the standard limit of Chromium discharge defined/ accorded by Environmental Protection Agency.

For many years organophosphate pesticides considered the main option for a lot of people in many countries to
manage different pests. It's more than 70 years now and OPs still use with certain purposes in gardens, fields and greenhouses as crop protection agents, or even at houses as public health agents. Thus, year after year and with the repeating usage of organophosphate agents many problems were appeared as a result to excessive use of pesticides. The adverse effects of
pesticides usage represented in the effects on human health, environment, pesticides residue in crops and soil & water
contaminated by these pesticides. Therefore, it was necessary to throw a light on the risks that generated by irresponsible usage  of organophosphate pesticides.

Although marine algal bioassays based on growth rate inhibition over 72-96 h have been widely used to assess the toxicity of contaminants in waters and sediments, changes in pH over the test duration can lead to changes in contaminant speciation and consequently an under-or over-estimation of toxicity. In addition, high cell densities are used in order to obtain a detectable response, further reducing the tests' environmental relevance in marine waters. There is a need for rapid acute tests with ecologically relevant test endpoints that may be used as surrogates for longer-term chronic tests. This study compares the sensitivity and reproducibility of a rapid marine dinoflagellate (Pyrocystis lunula) bioluminescence test (QwikLite TM ) with standard algal growth rate bioassays (Nitzschia closterium and Entomoneis c.f. punctulata) using ammonia and several antifouling agents (tributyltin [TBT], copper, and diuron) as reference toxicants. QwikLite was of similar sensitivity to ammonia as standard algal growth rate tests, but was less sensitive to copper, diuron and TBT, with 24-h EC50 values of 10 6 1.1 mg N/L, 0.128 6 0.021 mg Cu/L, 19 6 13 mg diuron/L, and 0.226 6 0.028 mg TBT/L. Inter-test precision using different batches of P. lunula was generally acceptable. On the basis of NOEC values, QwikLite TM was more sensitive to copper and ammonia at 258C than at 218C. QwikLite TM shows promise as a rapid, inexpensive screening test for acute toxicity of contaminants in marine environments. # 2008 Wiley Periodicals, Inc. Environ Toxicol 23: 617-625, 2008.

Quand l’Homme a commencé à faire de l’agriculture, il a d’abord appris à combiner les plantes, de façon à ce qu’elles se protègent naturellement. Depuis l’Antiquité, l’Homme a commencé à utiliser des pesticides, comme le souffre ou l’arsenic, en quantités juste suffisantes pour l’aider à protéger ses champs.
Apres la deuxième guerre mondiale, le taux de la famine ne cessa d’augmenter , le nombres des terres cultivées augmentes mais le résultats n’est pas suffisants , donc place aux produits miracles « les pesticides  » le rendement augmente la famine diminue mais  cette solution deviens un problème aujourd’hui  l’utilisation démesurée des pesticides est remise en cause, des chercheurs ont prouvé que  les pesticides peuvent avoir des effets négatifs sur l’environnement et sur la santé humaine

Acute toxicity tests of five metals (aluminum, cadmium, iron, lead, zinc) were performed to determine LC50 values in two
species of freshwater rotifers: Asplanchna brigthwellii and its prey Brachionus calyciflorus. We conducted the tests
using neonates less than 24 hr-old, each test consisted of five replicates, negative control and five metal concentrations
(Al, Cd, Fe, Pb, Zn). We found that the prey rotifer B. calyciflorus was more sensitive to Al, Cd, Pb and Fe than the
predator rotifer A. brightwellii. For both rotifers Cd was the most toxic of the five metals. Our B. calyciflorus strain is
sensitive when compared with other B. calyciflorus strains and other species and genera of the family Brachionidae. In
the other hand, LC50 values of A. brigthwellii are compared with rotifer and copepod predators.

Formaldehyde (FHO) is a multipurpose chemical that is an eye, nose, throat and skin irritant, sensitizer and allergen, as well as a class 1 human carcinogen. Brazilian hair treatments, containing high levels of FHO (up to 11%), have become regularly used that have the potential to expose clients to toxic levels in excess of current regulatory standards. We report on a patient who underwent a single hair treatment and subsequently developed an autoimmune disease. We review the relevant literature on autoimmune disease and formaldehyde exposure. Our case adds to existing knowledge and suggests that physicians ask their patients about commercial products that contain formaldehyde when diagnosing autoimmune conditions.

Coal tar is a significant product generated from coal pyrolysis. Coal tar can be utilized as raw materials for various industries. It is also a type of raw material from which phenols, naphthalenes, and anthracene can be extracted. The present study was designed to investigate the possibility of coal tar creosote to induce oxidative stress and biochemical perturbations in rat liver and the role of rosemary (Rosmarinus officinalis) in ameliorating its toxic effects. Male Wister Albino rats were randomly divided into four groups of seven each, group I served as control; group II treated with rosemary (10 mL of water extract/kg BW for 21 days), group III received coal tar creosote (200 mg/4 mL olive oil/kg BW for 3 days), and group IV treated with both rosemary and coal tar creosote. The administration of coal tar creosote significantly caused elevation in lipid peroxidation (LPO) and reduction in the activities of glutathione peroxidase (GPx), glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT), and glutathione S-transferase (GST). A significant decrease in reduced glutathione (GSH) content was also observed. Liver aminotransferases aspartate transaminase (AST) and alanine transaminase (ALT)] and alkaline phosphatase (AlP) were significantly decreased while lactate dehydrogenase (LDH) was increased. Rosemary pretreatment to coal tar creosote-treated rats decreased LPO level and normalized GPx, GR, SOD, CAT, and GST activities, while GSH content was increased. Also, liver AST, ALT, AlP, and LDH were maintained near normal level due to rosemary treatment. In conclusion, rosemary has beneficial effects and could be able to antagonize coal tar creosote toxicity.

The present study was planned aiming to investigate the effects of atrazine
herbicide exposure on stress biomarkers acetylcholinesterase activity (AchE) and
cortisol, oxidative stress responses and the histopathological changes in liver of
female Clarias gariepinus and the ameliorative effect of vitamin E supplementation
(240mg/kg diet) on the degree of atrazine sublethal toxicity (1.37mg/l) for 6 weeks.
Chronic exposure to atrazine revealed a marked inhibition in the activity of AchE.
But, significant increase of serum cortisol level was recorded. Moreover, atrazine
exposure was associated with a marked induction of oxidative damage in liver tissue
as evidenced by increased level of lipid peroxidation (LPO) and reduced glutathione
(GSH) content. Atrazine exposure also led to a significant increase in the activities of
catalase (CAT) and superoxide dismutase (SOD).Furthermore, histopathological
examination of the liver of exposed fish showed dilatation and congestion of blood
vessels, fatty degeneration, necrosis and pyknotic nuclei of hepatocytes. However,
fish fed diet supplemented with vitamin E exhibited protective effect by minimizing
the atrazine-induced toxicity, through measured values more or less similar to the
control group fish.
Key words: Atrazine, Clarias gariepinus, Cortisol, Oxidative stress, Histopathology

Nitrite is a compound with a high toxicity to aquatic animals. Several anthropogenic pollution sources are increasing the concentrations of this component of the nitrogen cycle. Despite this toxicity, there is little available literature on its effects on freshwater invertebrates. Laboratory bioassays were performed to obtain data on the lethal effects of nitrite to three species of freshwater invertebrates: the planarian Polycelis felina and the amphipods Echinogammarus echinosetosus and Eulimnogammarus toletanus. The LC50, LC10, and LC0.01 values (mg/L NO2N) at 24, 48, 72, and 96 h were calculated for each species. E. toletanus and E. echinosetosus were the most sensitive species, with 96 h LC50 values of 2.09 and 2.59 mg/L NO2N, respectively. In contrast, the planarian P. felina showed a higher tolerance to nitrite, with a 96 h LC50 value of 60.0 mg/L NO2N. The obtained results were compared with the reported nitrite data for other freshwater invertebrates. This study may contribute to a more appropriate assessment of the ecological risk of this compound in freshwater ecosystems. © 2006 Wiley Periodicals, Inc. Environ Toxicol 21: 90–94, 2006.

High level of heavy metal contaminants in air is known to cause serious health problems if remained unchecked for a long period of time. Anthropogenic activities such as vehicular emissions and number of industries are responsible for increasing the level of heavy metals. The aim of the present study was to biologically monitor the level of heavy metal contamination by spider webs. These sites were selected based on variable traffic volume and number of industries. Atomic absorption spectrometry (AAS) was used for the analysis of metal pollution content. The study determined that the level of heavy metals at the selected sampling sites were several folds higher than that at the control site and in previously reported literature. Pb was determined to be the most abundant heavy metal, while Thokar Niaz Baig was reported as the most contaminated site. These elevated levels of metal contaminants are associated with heavy traffic flow, number of industries and constructional activities in the respective areas.

A group contribution method has been developed that uses the LC50 values (measured for fathead minnow) for 130 diverse organic compounds. The 130 selected compounds were constituted from 16 chemical groups with -log(LCSO) values ranging from 0.85 to 6.09. The method was then used to predict the LC50 values for 10 additional compounds, not in the training set, with good agreement between the predicted and measured values.