Study of the carbonaceous aerosol and morphological analysis of fine particles along with their mixing state in Delhi, India: a case study.

Because of high emissions of anthropogenic as well as natural particles over the Indo-Gangetic Plains (IGP), it is important to study the characteristics of fine (PM2.5) and inhalable particles (PM10), including their morphology, physical and chemical characteristics, etc., in Delhi during winter 2013. The mean mass concentrations of fine (PM2.5) and inhalable (PM10) (continuous) was 117.6 ± 79.1 and 191.0 ± 127.6 µg m(-3), respectively, whereas the coarse mode (PM10-2.5) particle PM mass was 73.38 ± 28.5 µg m(-3). During the same period, offline gravimetric monitoring of PM2.5 was conducted for morphological analysis, and its concentration was ~37 % higher compared to the continuous measurement. Carbonaceous PM such as organic carbon (OC) and elemental carbon (EC) were analyzed on the collected filters, and their mean concentration was respectively 33.8 and 4.0 µg m(-3) during the daytime, while at night it was 41.2 and 10.1 µg m(-3), respectively. The average OC/EC ratio was 8.97 and 3.96 during the day and night, respectively, indicating the formation of secondary organic aerosols during daytime. Effective carbon ratio was studied to see the effect of aerosols on climate, and its mean value was 0.52 and 1.79 during night and day, indicating the dominance of absorbing and scattering types of aerosols respectively into the atmosphere over the study region. Elemental analysis of individual particles indicates that Si is the most abundant element (~37-90 %), followed by O (oxide) and Al. Circularity and aspect ratio was studied, which indicates that particles are not perfectly spherical and not elongated in any direction. Trajectory analysis indicated that in the months of February and March, air masses appear to be transported from the Middle Eastern part along with neighboring countries and over Thar Desert region, while in January it was from the northeast direction which resulted in high concentrations of fine particles.

Comparative toxicity of carbaryl, carbofuran, cypermethrin and fenvalerate in Metaphire posthuma and Eisenia fetida -a possible mechanism.

To establish the use of Metaphire posthuma as a sensitive test model for ecotoxicological studies, acute toxicity testing of carbaryl, carbofuran, cypermethrin and fenvalerate on Eisenia fetida and Metaphire posthuma were carried out. Two different types of bioassays, contact filter paper toxicity and soil toxicity bioassays were used to determine LC50 values for these insecticides. Among the tested chemicals, carbofuran was the most toxic to both the earthworm species. In paper contact method, 72 h-LC50 values of carbofuran in M. posthuma and E. fetida were found to be 0.08 µg/cm(2) and 1.55 µg/cm(2) respectively while in soil test, 14-d LC50 values were 0.49 mg/kg and 21.15 mg/kg respectively. On comparing the toxicity data of these chemicals for both the earthworm species, M. posthuma was found to be more sensitive than E. fetida. Based on the acute toxicity data, the order of toxicity of insecticides in both the test procedures was carbofuran>cypermethrin>carbaryl>fenvalerate for M. posthuma whereas for E. fetida it was carbofuran>carbaryl>fenvalerate>cypermethrin. Morphological changes also appeared in the organisms exposed to these chemicals which were more pronounced in M. posthuma at lower concentrations than E. fetida in both the test procedures. The results of the present study advocates the use of M. posthuma for ecotoxicity studies, being a more sensitive and reliable model than E. fetida. Based on the data on partial atomic charges, structural features and spectroscopic studies on carbaryl and carbofuran, a possible mechanism of toxicity of carbamate insecticides in earthworm was proposed.

Effect of synergist piperonyl butoxide (PBO) on the toxicity of some essential oils against mosquito larvae.

Effect of a known synergist piperonyl butoxide on the toxicity of steam distillate essential oils of Jamarosa (Cymbopogan nardus), Pacholli (Pogostemon pacholli), Basil (Ocimum basilicum), and Peppermint (Mentha pipreta) plant species against Anopheles stephensi larvae were evaluated. The purpose of the present study was to identify the insecticidal potential of these oils against mosquito larvae. The Piperonyl Butoxide (PBO) was used to enhance the activity of these oils with the aim of developing essential oil based formulations. The bioassays of these oils with and without PBO were performed against late 3rd instar larvae of An. stephensi. The LC50 values against An. stephensi were 44.19 ppm for Ocimum basilicum oil, followed by, Mentha pipreta, Cymbopogan nardus, and Pogostemon pacholli oil which gave LC50 values above 250 ppm. Thus in the present study the Ocimum basilicum oil was found to be most effective, whereas Pogostemon pacholli oil was found to least effective against mosquitoes for larvicidal action. The effect of synergist PBO led to the enhancement of toxicity of oils, the LC50 value for Ocimum basilicum were reduced from 44.19 ppm to 23.87 ppm. Similarly the oil of Pogostemon pacholli showed most significant results where the LC50 value was > 250 ppm it was reduced to 50 ppm with PBO.

Effect of synergist piperonyl butoxide (PBO) on the toxicity of some essential oils against mosquito larvae.

Effect of a known synergist piperonyl butoxide on the toxicity of steam distillate essential oils of Jamarosa (Cymbopogan nardus), Pacholli (Pogostemon pacholli), Basil (Ocimum basilicum), and Peppermint (Mentha pipreta) plant species against Anopheles stephensi larvae were evaluated. The purpose of the present study was to identify the insecticidal potential of these oils against mosquito larvae. The Piperonyl Butoxide (PBO) was used to enhance the activity of these oils with the aim of developing essential oil based formulations. The bioassays of these oils with and without PBO were performed against late 3rd instar larvae of An. stephensi. The LC50 values against An. stephensi were 44.19 ppm for Ocimum basilicum oil, followed by, Mentha pipreta, Cymbopogan nardus, and Pogostemon pacholli oil which gave LC50 values above 250 ppm. Thus in the present study the Ocimum basilicum oil was found to be most effective, whereas Pogostemon pacholli oil was found to least effective against mosquitoes for larvicidal action. The effect of synergist PBO led to the enhancement of toxicity of oils, the LC50 value for Ocimum basilicum were reduced from 44.19 ppm to 23.87 ppm. Similarly the oil of Pogostemon pacholli showed most significant results where the LC50 value was >250 ppm it was reduced to 50 ppm with PBO.

In vivo cytogenetic effects of a commercially formulated mixture of cypermethrin and quinalphos in mice.

In vivo cytogenetic effects of commercially formulated cypermethrin (CYP, synthetic pyrethroid insecticide) and/or quinalphos (QUI, organophosphate insecticide), generally used in combination, were examined through chromosomal aberrations (CA) and micronucleus test (MT) in mice. Male mice were orally gavaged to a single dose of CYP/QUI commercial mixture (22, 44 or 67 mg/kg b.wt.) for 24h (CA) or 48 h (MT). Based on the concentrations of active ingredients of CYP and QUI present in the test doses of CYP/QUI mixture, mice were orally exposed to 0.66, 1.32 and 2 mg/kg of CYP or 4.4, 8.8 and 13.4 mg/kg of QUI. For reference, a group of five mice was intraperitoneally administered to cyclophosphamide (20 or 50 mg/kg) or orally gavaged to peanut oil for vehicle control. Exposure of CYP/QUI mixture inhibited the mitotic index (MI) and induced CA in a dose-dependent manner at 24 h; however, significant (p<0.01 or 0.001) frequencies of CA were observed at 44 mg/kg onwards, whereas inhibition of MI at 67 mg/kg. Independent exposure of QUI at 8.8 mg/kg onwards also significantly (p<0.01 or 0.001) inhibited MI and induced CA, whereas CYP at 2 mg/kg (highest concentration in CYP/QUI mixture) inhibited MI significantly but failed to induce CA. Chromatid breaks and fragments found to be frequent aberrations in all the test groups. Treatment of CYP/QUI mixture also induced micronucleus formation dose-dependently at 48 h, yet statistically significant (p<0.001) frequencies of micronucleated polychromatic erythrocytes (MNPCE) were observed at 44 mg/kg onwards. QUI (8.8 and 13.4 mg/kg) alone also induced significant frequencies of MNPCE, whereas frequencies of MNPCE observed with the CYP even at 2 mg/kg were comparable to that of vehicle control. Present findings indicate the genotoxicity potential of CYP/QUI mixture and suggest that the simultaneous presence of the toxic doses of CYP and QUI can lead to synergistic genotoxicity in mice and may pose mutagenic risk in human beings.

Cytogenetic effects of commercial formulation of cypermethrin in root meristem cells of Allium sativum: spectroscopic basis of chromosome damage.

To validate the use of Allium sativum as a sensitive test model for genotoxicity, the cytogenetic effects of a commercial formulation of the pyrethroid insecticide, cypermethrin, were evaluated in the root meristem cells of A. sativum. Ultraviolet (UV) and Fourier transform infrared (FTIR) spectral measurements were also carried out to understand the interaction of cypermethrin with DNA. In a preliminary toxicity assay, the EC50 for Allium root growth was estimated to be 8 ppm. For the cytogenetic assay, root meristem cells were exposed to 1, 2, 4, 8 and 16 ppm of the test compound for 24 h, and either processed immediately for analysis or incubated in water for 24 h of recovery and then processed. Cells analyzed immediately after the exposure had a significant, dose-dependent inhibition of mitotic index (MI) and induction of mitotic and chromosomal aberrations (MAs and CAs). The 24 h recovery period reduced the effect of the test compound on the MI and percent aberrations; however, cells exposed to 8 and 16 ppm showed a significant frequency of aberrations despite the recovery period. One part per million cypermethrin was consistently negative in the assay. The data indicate that higher doses of cypermethrin produce toxicity, CAs and MAs in A. sativum. The present study indicates that A. sativum is a sensitive and reliable test system. A bathochromic shift observed in UV absorption spectra reveals that cypermethrin binds with DNA. Role of vibrational modes of the active site in the recognition and reaction of cypermethrin with DNA has been discussed. Based on spectroscopic data and structural properties, a possible mechanism has been proposed for the interaction of cypermethrin with DNA resulting in chromosomal aberrations.

Comparative biomonitoring of leachates from hazardous solid waste of two industries using Allium test.

Hazardous industrial wastes are inevitable source of environmental pollution. Leachates from these wastes might contaminate the origins of potable water and affect human health. The study was carried out to determine the possible genotoxic effects of leachates from solid waste of a metal and dye industry using the Allium cepa chromosome aberrations assay. The 10% leachates were prepared from solid wastes obtained from both the industries and examined for the presence of heavy metal content and genotoxicity. To simulate the field and laboratory conditions, A. cepa bulbs were exposed through soil and aqueous medium for 48 h to 2.5-10% leachates. The results revealed that both metal waste leachate (MWL) and dye waste leachate (DWL) contained high concentrations of chromium, nickel and iron that significantly induced cytogenetic alterations. Significant inhibition of mitotic index (MI), inductions of chromosomal/mitotic aberrations (CA/MA) and micronuclei (MN) formation were found in all experimental groups exposed to MWL and DWL. The effects observed were concentration dependent and the frequency of aberrations was higher with treatment of MWL than DWL. The MI was severely inhibited at 10% aqueous exposure it was 4.59+/-0.69 (P<0.001) in MWL and almost half to that induced by DWL that was 8.62+/-0.69 (P<0.05). Significant frequency of CA/MA and MN induced by MWL was 14.21 (P<0.001) and 0.33 (P<0.001) whereas CA/MA and MN induced by DWL was 7.81 (P<0.001) and 0.13 (P<0.05) in the aqueous medium. The investigations inferred that abnormalities caused by MWL were higher than DWL both in soil and aqueous media. These toxic responses may have relied on raised heavy metal concentrations of metal-based than dye industrial wastes.

Role of molecular geometry, valence charge distribution and vibrational modes in bioactivity of cyclodiene insecticides.

Fourier transform infrared spectral measurement and complete normal mode calculations have been carried out for heptachlor and wedge modes have been identified. In addition, valence charge distributions have been obtained for aldrin, endrin, heptachlor, beta-endosulfan, cis-chlordane, trans-chlordane, photo-cis-chlordane and photo-trans-chlordane using CNDO/2 (complete neglect of differential overlap) molecular orbital calculations. A toxicity parameter has been defined as the product of the charge distribution and surface area of the corresponding active wedges, depending on the interacting structural features. The variation of this toxicity parameter is generally in order and in agreement with the reported measurements based on the corresponding order of observed LD50 values. Because of the structural features, the toxicity in these cases is a surface phenomenon rather than a volume effect as in the case of Gammexane, wherein the insecticide binds itself to membrane channels. Because the biological activity is a dynamic rather than a static phenomenon, it is expected that the normal modes involving the wedge atoms play an important role.

Genotoxic Effects of Diuron Contaminated Soil on the Root Meristem Cells of Allium sativum: A Possible Mechanism of Chromosome Damage.

Diuron, a persistant substituted urea herbicide, was tested in the root meristem cells of Allium sativum for the possible cytogenetic effects and to compare the sensitivity with Allium cepa. Test concentrations of diuron 22.5, 45.0, and 90.0 ppm were mixed in soil and the cloves of A. sativum were placed over diuron-contaminated soils. Root meristematic cells were sampled at 48 h to score Mitotic/Chromosomal aberrations and to analyze the effect on mitotic index (MI). Microscopic analyses revealed significant and dose-dependent induction of mitotic as well as chromosomal breaks. The frequency of mitotic aberrations was every time found much higher than that of chromosomal aberrations. Mild percentage of Micronucleated and Binucleated cells was observed, as MI also declined during the analysis. Based on the data of valence charge densities on the atoms of herbicide molecule and spectroscopic studies, a possible mechanism of interaction of diuron with DNA molecule for chromosomal aberrations has been proposed.

Effect of cybil on reproductive success of wild Drosophila melanogaster.

Cybil (a synthetic pyrethroid) was used to assess its impact on the reproductive success in F1 and F2 generations of wild Drosophila melanogaster. The LC50 has been estimated as 0.0267 microl/100 ml food. Reproductive success has been found to be affected in addition to fecundity and pupation following toxicity of cybil.

Evaluation of cytogenetic effects of isoproturon on the root meristem cells of Allium sativum.

OBJECTIVE: To validate the use of Allium sativum as a reliable test model for genotoxicity, isoproturon, a substituted phenylalkylurea herbicide, was evaluated on the root meristem cells by this plant system. METHOD: Test concentrations were selected by determining EC50 and root tips were exposed to various concentrations for 6 or 24 hr. EC50 concentration was calculated to be 70. 8 ppm for the root growth. In addition to root growth retardation exposure to isoproturon induced morphological changes like discolouration and stiffness of roots. RESULTS: Exposure to various experimental concentrations of isoproturon (35-280 ppm), including EC50, significantly and dose-dependently inhibited the mitotic index and induced chromosome breaks/mitotic aberrations at 6 or 24 hr. CONCLUSION: The frequency of aberrations was found to be decreased in a dose dependent manner at 24 or 48 hr post exposure, however in comparison of control cells the frequency of aberrations was considerably high which indicates genotoxicity potentials of isoproturon. Further, present study also suggests that Allium sativum is a sensitive, efficient, and reliable test system for measuring the genotoxicity potential of environmental chemicals.

Toxicity of Certain Penta-Coordinated Organotin(IV) and Tetra-Coordinated Tin(II) Complexes of Heterocyclic beta-Diketones Against the Larvae of Aedes Aegypti (Liston).

Some organotin(IV) and tin(II) complexes of composition R(3)Sn[R'COC:CON(C(6)H(5))N:CCH(3)] (where R=C(4)H(9), R'=CH(3), C(3)H(5), p-ClC(6)H(4); R=C(6)H(5), R'=C(6)H(5) and p-ClC(6)H(4)) and Sn[p-ClC(6)H(4)COC:CON(C(6)H(5))N:CCH(3)](2) were screened for their toxicity against Aedes aegypti larvae. Organotin(IV) complexes were more active than tin(II) complexes.

An ultrastructural study of the prostate gland of megascolicid earthworm Lampito mauritii (Kinberg).

The ultrastructure of prostate gland of Lampito mauritii revealed two types of secretory cells. Type 1 cells with a broad basal region and a long apical region contain electron dense oval secretory granules with an increased density at the core region. Numerous electron lucent granules with fine filamentous and electron dense amorphous materials also occur at the basal region of these cells. Type 2 cells contain electron lucent mucous-like secretory granules. This cell type contains exceptionally large Golgi complexes having 20-23 stacked cisternae. Both cell types open into a common lumen and numerous microtubules are visible at the apical end. Junctional complexes, such as desmosomes and septate junctions, are observed in this glandular tissue.

Normal vibrations and valence charge distribution in relation to bioactivity of gammexane.

Normal coordinate analysis has been made for gammexane using the Wilson's G-F matrix method with Urey-Bradley force field. Molecular orbital calculations using CNDO/2 method have also been carried out for the five isomers of hexachlorocyclohexane to give the valence charge densities on the atoms of the molecules. A toxicity parameter that takes into account a shape factor and the valence charge density on the atoms has been defined. On the toxicity scale so defined the gamma-isomer alone has a significant value.

Hydrolytic enzymes of rhesus placenta during Plasmodium cynomolgi infection: ultrastructural and biochemical studies.

Placenta in monkey demonstrated altered pathophysiology after P cynomolgi infection. The electronmicroscopic observations showed slight complete focal necrosis of the placental tissue, besides alterations in total protein, phosphatases and proteinases. These changes in cellular constituents of placenta during malaria infection may be responsible for malfunctioning of the organ and in turn, abnormal development of foetus.

Central hyperthermic effect of arsenic in rabbits.

Hyperthermic effect of arsenic was investigated in rabbits. Injections of arsenic trioxide (0.0001 to 0.1 micrograms) into a lateral cerebral ventricle of the rabbit evoked a dose-dependent hyperthermia, respiratory stimulation and peripheral vasodilatation. Heat loss through respiratory stimulation and peripheral vasodilatation appeared responsible for the long latent period and the slight hypothermia sometimes obtained during this period as these effects followed the same time course. These effects were centrally mediated as demonstrated by the lack of efficacy of the same doses by the intravenous route. The hyperthermic effect of arsenic was antagonized by the sulphydryl donator, dimercaprol, the a-adrenoceptor blocking agent-phenoxybenzamine and the PG-synthesis inhibitor-aspirin. Multiple sites, for antagonistic effects of these substances can be explained by the action of arsenic in inactivating sulphydryl containing enzymes which are many and catalyze diverse biochemical reactions.