Pesticide residues in rain water from Hisar, India

Presence of pesticide residues was studied in rain water during 2002 employing multi residue analysis method by gas liquid chromatography equipped with ECD and NPD detectors and capillary columns. The presence of pesticide residues in surface aquatic system triggered the investigation of the presence of pesticides in rain water. A total of 13 pesticides were detected in rain water samples. Among the different groups of pesticides, organochlorines were present in the range of 0.041–7.060 ppb with maximum concentration of p,p’-DDT up to 7.060 μg l⁻¹. Synthetic pyrethroids were present ranging from 0.100 to 1.000 μg l⁻¹ and organophosphates in the range of 0.050–4.000 μg l⁻¹ showing maximum contamination with cypermethrin (1.000 μg l⁻¹) and monocrotophos (4.000 μg l⁻¹) of the respective groups. Almost 80% samples showed the residues above MRL of 0.5 ppb fixed for multi residues and on the basis of single pesticide, 16–50% samples contained residues above the MRL value of 0.1 ppb.     

Spatial Relationships Between Water Quality and Pesticide Application Rates in Agricultural Watersheds

Pesticide applications to agricultural lands in California, USA, are reported to a central data base, while data on water and sediment quality are collected by a number of monitoring programs. Data from both sources are geo-referenced, allowing spatial analysis of relationships between pesticide application rates and the chemical and biological condition of water bodies. This study collected data from 12 watersheds, selected to represent a range of pesticide usage. Water quality parameters were measured during six surveys of stream sites receiving runoff from the selected watershed areas. This study had three objectives: to evaluate the usefulness of pesticide application data in selecting regional monitoring sites, to provide information for generating and testing hypotheses about pesticide fate and effects, and to determine whether in-stream nitrate concentration was a useful surrogate indicator for regional monitoring of toxic substances. Significant correlations were observed between pesticide application rates and in-stream pesticide concentrations (p < 0.05) and toxicity (p < 0.10). In-stream nitrate concentrations were not significantly correlated with either the amount of pesticides applied, in-stream pesticide concentrations, or in-stream toxicity (all p > 0.30). Neither total watershed area nor the area in which pesticide usage was reported correlated significantly with the amount of pesticides applied, in-stream pesticide concentrations, or in-stream toxicity (all p > 0.14). In-stream pesticide concentrations and effects were more closely related to the intensity of pesticide use than to the area under cultivation.     

Spectrophotometric determination of indiumin zinc effluent

A new extraction-spectrophotometric method for the determination of indium at ppb level in zinc effluent is described. It is based on quantitative extraction (51.2–99.2%) of the tetrabromoindate complex with toluene solution of N,N-diphenylbenzamidine and its nine analogous from sulphuric acid solutions, which allowed the extract to react with basic dye (i.e. brilliant green, malachite green, crystal violet) solution in sequence. Among the basic dyes tested, brilliant green gave the most sensitive colour reaction. The value of molar absorptivity of the amidine bromoindate extracts with brilliant green lie in the range of (0.53–1.03)×10⁵ l mole^-1 cm^-1 at absorption maximum, 630–640. With the most sensitive compound, N-(2-methyl-phenyl)-N-phenylbenzamidine(APPBA), the detection limit of the method is 13 ppb. The method is free from interferences of almost all ions associated with indium. The method has been applied for the determination of indium to zinc-effluent.     

31P-NMR evaluation of organophosphorus pesticides degradation through metal ion promoted hydrolysis

The degradation of some organophosphorus pesticides (OPPs) in the presence of metal ions was studied by ³¹P-NMR spectroscopy. Both ³¹P-NMR and gas chromatography/mass spectroscopy results were used in order to determine the nature of metabolites formed after degradation. The degraded organophosphorus pesticide were investigated for chlorpyrifos and phoxim in the presence of several metal ions including Hg²⁺, Cu²⁺, Cd²⁺, Ni²⁺, Pb²⁺, and Ag⁺. ³¹P-NMR results indicated Ag⁺ and Hg²⁺ ion promoted degradation of OPPs and other metal ions formed complex with OPPs and cannot degrade OPPs. We found that the degradation of chlorpyrifos and phoxim with Ag⁺ or Hg²⁺ led to the formation of O,O-diethyl-O-methyl phosphorothionate, (C₂H₅O)₂(CH₃O)PS, at metal ion/pesticide mole ratios ≤1.0 and completely decomposed at a higher mole ratio of 10. Finally, the method was successfully applied to the degradation study of a number of technical and formulated pesticides in the presence of Ag⁺ ion at a metal ion/pesticide mole ratio of 10.     

Improved dissipation kinetic model to estimate permissible pre-harvest residue levels of pesticides in apples

Prediction of residual concentrations of applied pesticides during the pre-harvest period may be required to ensure the safety of agricultural products. In this study, time-dependent dissipation trends of carbaryl (CB), kresoxim-methyl (KM), flubendiamide (FB), flufenoxuron (FN), bitertanol (BT), and chlorantraniliprole (CN) applied to apples at recommended and threefold greater doses were modeled to estimate pre-harvest residue limit concentrations (C_PHRL) indicating permissible pesticide concentrations during the pre-harvest period. Double-exponential (DE) model results best fit the dissipation trends of all tested pesticides (correlation coefficients of 0.91–0.99) compared to zero-, first-, and second-order models. Among the pesticides examined, CB half-lives in apples of 2.9 and 6.6 days were the shortest, while those of FN (21.1–32.7 days) were the longest. The C_PHRL values for each pesticide in apples were estimated with DE model parameter values and could be used to determine harvest dates for safe apples with pesticide concentrations below their maximum residue limits. Application of the DE model for C_PHRL calculation provides more accurate information for farmers to produce agricultural products safe from pesticide residues.     

Systematic Biases in Measurement of Urban Nitrogen Dioxide using Passive Diffusion Samplers

Measurement of nitrogen dioxide using passivediffusion tube over 22 months in Cambridge, U.K. areanalysed as a function of sampler exposure time, andcompared with NO₂ concentrations obtained from aco-located chemiluminescence analyser. The averageratios of passive sampler to analyser NO₂ at acity centre site (mean NO₂ concentration 22 ppb)are 1.27 (n = 22), 1.16 (n = 34) and 1.11 (n = 7) forexposures of 1, 2 and 4-weeks, respectively. Modellingthe generation of extra NO₂ arising from chemicalreaction between co-diffusing NO and O₃ in thetube gave a ratio (modelled/measured) of 1.31 for1-week exposures. Such overestimation is greatest whenNO₂ constitutes, on average, about half of totalNO_x (= NO + NO₂) at the monitoring locality.Although 4-week exposures gave concentrations whichwere not significantly different from analyserNO₂, there was no correlation between thedatasets. At both the city-centre site and anothersemi-rural site (mean NO₂ concentration 11 ppb)the average of the aggregate of four consecutive1-week sampler exposures or of two consecutive 2-weeksampler exposures was systematically greater than fora single 4-week exposure.The results indicate two independent and opposingsystematic biases in measurement of NO₂ bypassive diffusion sampler: an exposure-timeindependent chemical overestimation with magnitudedetermined by local relative concentrations of NO andO₃ to NO₂, and an exposure-time dependentreduction in sampling efficiency. The impact of theseand other potential sources of systematic bias on theapplication of passive diffusion tubes for assessingambient concentrations of NO₂ in short (1-week)or long (4-week) exposures are discussed in detail.     

A new system to bioassay pesticides present in the surface microlayer using floating propagules of an aero-aquatic hyphomycetous fungus Pseu doaegerita matsushimae

The surface microlayer often contains pesticides at levels which may be more than one hundred thousand times those sampled in the remainder of the water column. Standard bioassay systems cannot asses these pesticides since no system yet devised has made use of organisms inhabiting the surface microlayer. Using floating propagules of Pseudoaegerita matsushimae, an aeroaquatic hyphomycetous fungus, a bioassay system was devised in which the percentage germinations of such propagules after exposure to various levels of pesticides were plotted to produce a dosegermination scale onto which subsequent data could be fitted. The following pesticides and pesticide mixtures were used: PCP; DDT; Methoxychlor; Bis(tributyl)tin Oxide; Malathion; Captan; 1 part PCP/1 part DDT; 2 parts PCP/1 part DDT; 3 parts PCP/1 part DDT; 2 parts DDT/1 part PCP; 3 parts DDT/1 part PCP; 1 part PCP/1 part Methoxychlor; 2 parts PCP/1 part Methoxychlor; 3 parts PCP/1 part Methoxychlor; 2 parts Methoxychlor/1 part PCP; 3 parts Methoxychlor/1 part PCP. The bioassay system revealed increased sensitivity to pesticides and pesticide mixtures which affected respiratory metabolism. Some pesticide mixtures were more effective in inhibiting germination than their individual components while others appeared much less toxic to the propagules than their unassisted components.     

Toxicity of a complex mixture of atmospherically transported pesticides to Ceriodaphnia dubia

The presence of several anthropogenic chemicals has been documented in the atmosphere of the Canadian prairies. The deposition of these chemicals as a mixture is of importancesince little is known of the combined effects of these chemicalson aquatic organisms. This study was designed to evaluate theacute and chronic toxicity of a complex mixture of nineatmospherically transported pesticides to Ceriodaphniadubia. The nine selected pesticides (bromoxynil, dicamba, 2,4-D,MCPA, triallate, trifluralin, pentachlorophenol, lindane, and4,4-DDT) were detected in appreciable quantities in dryatmospheric deposits. The concentration of each pesticide in themixture was based on maximum measured daily dry deposition ratesfor central Canada, except for pentachlorophenol, which wasestimated based on atmospheric concentrations. The 48-h LC50estimate for C. dubia exposed to the pesticide mixture was174.60 g L^-1 (340 times the measured total dry deposition concentration). The estimated NOEC and LOEC for bothsurvival and reproduction, as determined in the 7-d chronic toxicity test, were 51.3 (100 times) and 154 g L^-1 (300 times), respectively. A basic risk assessment, using the toxic unit approach, suggested that the toxicity of the pesticide mixture was mainly due to 4,4-DDT. Overall, this atmospherically transported complex mixture of pesticides appearsto pose a negligible toxicological risk to non-target aquatic invertebrates such as zooplankton.     

Simultaneous Measurements of Atmospheric Pollutants and Visibility with a Long-Path DOAS System in Urban Areas

In this paper, the applicability of a Long-Path Differential Optical Absorption Spectroscopy (LP-DOAS) system was checked for the feasibility of the simultaneous measurement of trace gases (such as O₃, NO₂, SO₂, and HCHO) and atmospheric visibility (light extinction by aerosols) in Asian urban areas. Field studies show that an LP-DOAS system can simultaneously measure the key pollutants (such as O₃, NO₂, SO₂, and HCHO) at detection limits in the ppb/sub-ppb range as well as the Mie extinction coefficient with an uncertainty of 0.1 km^–1 at time resolution of a few minutes. It is thus concluded that the use of LP-DOAS system is feasible for simultaneous measurement of gaseous pollutants as well as an atmospheric extinction coefficient which is tightly bound to fine particulate concentration.     

Risk Assessment of Organic Pesticides Pollution in Surface Water of Hangzhou

Advances in research on pollution of organic pesticides (OPs) in surface water, pollution survey and risk assessments of organochlorine pesticides (OCPs) and organophosphorus pesticides (OPPs) of surface water in Hangzhou are conducted. Total concentrations of dichloro-diphenyl-trichloroethane (DDT) and hexachloride-benzene (HCH) in surface water were observed to be 0–0.270 μg/L and 0–0.00625 μg/L respectively. DDE, as a metabolite of DDT and many species of OPP_S were determined in some samples of surface water. Parathion, the main pollutant among OPPs in surface water of Hangzhou, was observed to be 0–0.445 μg/L. Based on these experimental results, health risk assessments on the organic pollution are developed. It is observed that the total risk “R ^T” at present time of surface water in Hangzhou is mainly contributed by organophosphorus pesticides, especially Parathion; HCH and DDT are not the main contaminants; on the contrary, organophosphorous pesticides, especially Parathion, must be of concern at the present time.     

Pesticide burden on some insects of economic importance in Lucknow (India)

Some insects of economic importance from Lucknow (India) have been investigated for their pesticide burden. Chlorinated pesticide residues of DDT, BHC and aldrin along with their metabolites and isomers have been detected in crop pollinating insects, honeybees (Apis indica) and butterflies (Danais chrysippus and Eurema sp.) and predators, dragonfly (Platythemis sp.) and wasps (Polistes herebreus). DDT and their metabolites were present in concentrations which varied from 231–796 ng g^–1, followed by BHC (10–60 ng g^–1), and aldrin (0.26–6.68 ng g^–1). This finding is likely to stimulate newer interest in the area of pesticide research and start meaningful investigation to find if bioaccumulated pesticides would have adverse impact on otherwise beneficial potentials of such insects in our ecosystems.     

Sorption of carbon tetrachloride,ethylene dibromide,and trichloroethylene on soil and clay

The sorption of carbon tetrachloride, ethylene dibromide, and trichloroethylene in two silty clay loam soils and aluminium (Al³⁺) or calcium (Ca²⁺) saturated montmorillonite clay was studied. When the adsorbents were exposed to environmental levels of these chemicals (10 to 1000 ppb in water) the amounts of each of the chemicals sorbed were 6% or less of that available except for a 17% sorption of trichloroethylene by Al-saturated clay. In the case of the Ca-saturated clay, there was no apparent sorption of carbon tetrachloride or trichloroethylene. When soil sorption was normalized based on the soil organic carbon content (K _oc) a correlation was found between the K _oc, water solubility, and octanol/water partitioning coefficients of the chemicals. However, carbon tetrachloride did not behave according to with the predicted relationships.     

Monitoring and risk assessment of pesticides in a tropical river of an agricultural watershed in northern Thailand

The increasing application of pesticides in the uplands of northern Thailand has increased the transfer of pesticides to surface water. To assess the risk of pesticide use for stream water quality, we monitored the concentrations of seven pesticides (atrazine, dichlorvos, chlorpyrifos, dimethoate, chlorothalonil, (α-, β-) endosulfan, cypermethrin) frequently used in the Mae Sa watershed (77 km²) in water and sediment samples over a period of one and a half years (2007–2008). All investigated pesticides were recorded in the river. Chlorpyrifos was detected most often in water samples (75 % at the headwater station), while cypermethrin was most often found in riverbed (86 %) and in all suspended sediment samples. The highest concentrations of the pesticides were detected during the rainy season. About 0.002 to 4.1 % by mass of the applied pesticides was lost to surface water. The risk assessment was based on the risk characterization ratio (RCR). The RCRs of dichlorvos in water, (α-, β-) endosulfan, and cypermethrin in water and sediments were higher than unity indicating that they are likely to pose a threat to aquatic ecosystem. Finally, we discuss the role of sampling design on ecotoxicological risk assessment. Our study shows that pesticide contamination of surface waters is an environmental issue in the Mae Sa watershed and that measures need to be undertaken to reduce the loss of pesticides from soil to surface waters.     

An assessment of air quality in Karachi,Pakistan

An atmospheric pollution survey was carried out at 13 sites in Karachi, Pakistan, simultaneously from 0600 h to 2100 h for 15 consecutive days in May 1990 which also included meteorological measurements. The monitoring sites were included along the prevailing wind patterns in Karachi. Carbon monoxide levels in the ambient air were found to reach 9–10 ppm along the busy urban streets whereas CO₂ level exceeded 370 ppm in these areas. Our survey indicates that NO₂ levels were exceeding U.S. ambient air quality standards. Maxmum NO₂ concentrations were observed (0.3–0.5 ppm) during the daytime from 0600 h to 2100 h. The surface ozone maximum around noon at the inland sites reached the levels of 40 ppb and 50 ppb respectively compared to upwind coastal Sites 1 level of 25 ppb. The Pb concentrations were approximately 3- to 7-fold higher than average, which corresponded well to urban air. Fossil fuel SO₄ (excess) and NO₃ were apportionally based on the assumption that these two anions were present as (NH₄)₂SO₄, and NH₄NO₃ in the aerosols. In the eastern part of the city atmospheric sulphate (SO₄) shows the combustion of coal as its source from the vicinity and downwind of a steel manufacturing plant.     

Pesticides residues in okra (non-target crop) grown close to a watermelon farm in Ghana

The study looked at the levels of pesticides in okra grown close to a watermelon farm herein referred to as a non-target crop. The watermelon received some pesticide application in the course of its cultivation, and the okra which was not meant to be sprayed was also affected by the pesticide. About 500 okra samples were collected for a period of 6 weeks and pesticides extracted with 1:1 n-hexane and dichloromethane which was analysed with Agilent 2222 GC/MS coupled with 389 auto-sampler. The results confirmed accumulation of significant levels of pesticides in the non-target crop (okra grown close to watermelon farm). Levels of organochlorine pesticides ranged from 3.10 to 7.60 μg/kg whilst the organophosphorus pesticides had levels ranging from 2.80 to 2016.80 μg/kg. The synthetic pyrethroid pesticide mean levels also ranged from 0.10 to 4.10 μg/kg and were below World Health Organization/Food and Agriculture Organization-recommended residue levels, and though not appearing to constitute a grave threat to life, their occurrence is a concern, and pre-emptive techniques must be developed to thwart the contaminations. Though the non- target crop was not treated directly with the pesticides, some level of contamination with organochlorine and organophosphorus pesticides persisted in the crops. It can be inferred that application of pesticides affected the adjoining crops, meaning that inter-cropping and mix-cropping might not be acceptable when one of the crops requires pesticide application. It is important for the farmers to be trained to ensure proper application of pesticide to minimise its impact on the health of consumers.     

Impacts of pesticides in a Central California estuary

Recent and past studies have documented the prevalence of pyrethroid and organophosphate pesticides in urban and agricultural watersheds in California. While toxic concentrations of these pesticides have been found in freshwater systems, there has been little research into their impacts in marine receiving waters. Our study investigated pesticide impacts in the Santa Maria River estuary, which provides critical habitat to numerous aquatic, terrestrial, and avian species on the central California coast. Runoff from irrigated agriculture constitutes a significant portion of Santa Maria River flow during most of the year, and a number of studies have documented pesticide occurrence and biological impacts in this watershed. Our study extended into the Santa Maria watershed coastal zone and measured pesticide concentrations throughout the estuary, including the water column and sediments. Biological effects were measured at the organism and community levels. Results of this study suggest the Santa Maria River estuary is impacted by current-use pesticides. The majority of water samples were highly toxic to invertebrates (Ceriodaphnia dubia and Hyalella azteca), and chemistry evidence suggests toxicity was associated with the organophosphate pesticide chlorpyrifos, pyrethroid pesticides, or mixtures of both classes of pesticides. A high percentage of sediment samples were also toxic in this estuary, and sediment toxicity occurred when mixtures of chlorpyrifos and pyrethroid pesticides exceeded established toxicity thresholds. Based on a Relative Benthic Index, Santa Maria estuary stations where benthic macroinvertebrate communities were assessed were degraded. Impacts in the Santa Maria River estuary were likely due to the proximity of this system to Orcutt Creek, the tributary which accounts for most of the flow to the lower Santa Maria River. Water and sediment samples from Orcutt Creek were highly toxic to invertebrates due to mixtures of the same pesticides measured in the estuary. This study suggests that the same pyrethroid and organophosphate pesticides that have been shown to cause water and sediment toxicity in urban and agriculture water bodies throughout California, have the potential to affect estuarine habitats. The results establish baseline data in the Santa Maria River estuary to allow evaluation of ecosystem improvement as management initiatives to reduce pesticide runoff are implemented in this watershed.     

Development of baseline (air quality) data in Pakistan

During 2003–2004, SUPARCO, the Pakistan Space and Upper Atmosphere Research Commission has conducted a year long baseline air quality study in country’s major urban areas (Karachi, Lahore, Quetta, Rawalpindi, Islamabad and Peshawar). The objective of this study was to establish baseline levels and behavior of airborne pollutants in urban centers with temporal and spatial parameters. This study reveals that the highest concentrations of CO were observed at Quetta (14 ppm) while other pollutants like SO₂ (52.5 ppb), NO _x (60.75 ppb) and O₃ (50 ppb) were higher at Lahore compared to other urban centers like Karachi, Peshawar etc. The maximum particulate (TSP) and PM10 levels were observed at Lahore (996 ug/m³ and 368 ug/m³ respectively), Quetta (778 ug/m³, 298 ug/m³) and in Karachi (410 ug/m³, 302 ug/m³). In all major cities the highest levels were recorded at major intersections and variations were directly correlated with traffic density. These pollutants showed highest levels in summer and spring while lowest were observed in winter and monsoon. A data bank has been generated for future planning and air pollution impact studies.     

Persistence and Distribution of Endosulfan under Field Condition

Rapid increase in industrialization and agricultural activities to meet the population need has led to environmental pollution. The major revolution in agricultural production is mainly due to increased use of pesticides and fertilizers. Soil act as a major sink for majority of pesticides applied on agricultural crops. Among the organochlorines, endosulfan is the most commonly used pesticide, hence this study concentrates on the persistence and distribution behaviour of endosulfan under field conditions. The result showed that the alpha endosulfan concentrations were very minimum (0.98 mg/kg of soil) in all the four fields under study (Nazarath, Othikadu, Ekkadu and Ekkadukandigai of Thiruvallur district, Tamil Nadu). Where as beta endosulfan concentration at the time of application was 6.39 mg/kg and declined to 0.8 mg/kg on soil at 150th day. The endosulfan sulfate concentration was 11.8 mg/kg in soil at 15th day and then concentration declined to 2.2 mg/kg at 150th day. Field run-off samples showed maximum residue levels (0.024 mg/l) at the early irrigation period. While plant foliar parts showed maximum concentrations of α-endosulfan (43.4 mg/kg), β-endosulfan (40.6 mg/kg) and endosulfan sulfate (20.1 mg/kg). At harvest stage, rice grain and husk also had lower concentrations of endosulfan sulfate (2.2 and 0.09 mg/kg), respectively.     

Evaluation of ogawa passive sampling devices as an alternative measurement method for the nitrogen dioxide annual standard in El Paso, Texas

Nitrogen Dioxide (NO₂) is a common urban air pollutant that results from the combustion of fossil fuels. It causes serious human health effects, is a precursor to the formation of ground level ozone, another serious air pollutant, and is one of the six criteria air pollutants established by the United States (U.S.) Clean Air Act (CAA). Ogawa Passive Sampling Devices (PSDs) for NO₂ were collocated and operated at six NO₂ Federal Reference Method (FRM) monitor locations in the El Paso, Texas area for the 2004 calendar year. Passive samples were taken at 2-week, 3-week, and 4-week intervals and compared against the continuously operating FRM monitors. Results showed that the collective NO₂ annual arithmetic mean for all passive monitors was identical to the NO₂ mean for all FRM monitors. Of the individual locations, three passive annual NO₂ means were identical to their corresponding FRM means, and three passive annual NO₂ means differed from their corresponding FRM means by only one part per billion (ppb). Linear correlation analysis between all readings of the individual NO₂ PSDs and FRM values showed an average absolute difference of 1.2 ppb with an r ² of 0.95. Paired comparison between high and low concentration annual NO₂ sites, seasonal considerations, and interlab quality control comparisons all showed excellent results. The ease of deployment, reliability, and the cost-savings that can be realized with NO₂ PSDs could make them an attractive alternative to FRM monitors for screening purposes, and even possibly an equivalent method for annual NO₂ monitoring. More tests of the Ogawa NO₂ PSD are recommended for different ecosystem and climate regimes.     

Pesticide residues in sediments and aquatic species in Lake Nokoué and Cotonou Lagoon in the Republic of Bénin

Lake Nokoué and Cotonou Lagoon are the most important and most productive continental freshwaters in Bénin, with an estimated fish production of over 2 tonnes per hectare in Lake Nokoué. Organochlorine pesticides are used in agriculture and to repel tsetse flies, malaria mosquitoes and other diseases raised. Sediment, fish, shrimp and oyster species were collected in Lake Nokoué and Cotonou Lagoon for pesticide residues analysis. The main pesticides identified in sediment were pp′-DDT and its metabolites pp-DDE and pp′-DDD, with residue levels between the detection limit and 24.4 μg/kg dry weight. Fish species commonly consumed such as Elops lacerta, Podamasys jubelini, Gobbienellus occidentalis, Ethmalosa fimbriata, Mugil cephalus and Hemichromis fasciatus were contaminated with residues of seven to nine pesticides, including pp-DDE, op′-DDD, pp′-DDD, op′-DDT, pp′-DDT, α-endosulfan, aldrin, dieldrin and γ-hexachlorocyclohexane. The levels ranged from detection limit to 289 ng/g lipid. The same pesticides were also detected in other aquatic species, such as shrimp and oysters. A summed risk assessment, comparing pesticide intake levels through fish consumption with tolerable daily intake levels proposed by the World Health Organization, showed in all cases a low risk for human health.