bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison Assessment of Water Use and Damage between Modern and Traditional Rice Irrigation Schemes: Case of Usangu Basin, Tanzania
Authors: Machibya Magayane , Mdemu Makarius
Published: October 2008

Water management and competition between users in water scarce river basins is a major challenge facing the human race. The inter dependence of users in such basins, necessitates a clear understanding of each user in relation to the location, the water demand, and the duration of water need. The understanding of these factors, together, is very important for the management of water resources in such basins without which, it is argued that, water is overused and wasted. As an example of this, the large modern and improved rice irrigation systems in Tanzania are believed to use water more efficient than the traditional irrigation systems. Yet, well-founded scientific analyses are a necessary part to quantify such beliefs as they can inform us whether the natural resource, in such systems, is properly utilized and managed or not. Likewise, such studies can allow us to quantify how much water is over used and thus the natural resource is unnecessarily degraded. This paper explores a study conducted in the Usangu basin, Tanzania, to investigate the gross and net needs for modern and traditional rice irrigation schemes, and the implications with regards to water resource management and damage. Problems relating to modernization of traditional smallholder irrigation systems and upstream - downstream water users are further discussed. The paper concludes from the study that modern irrigation schemes are inefficient compared to traditional irrigation schemes. Also modernization of traditional schemes in the study area have resulted into over abstraction and reduced productivity of water. Looking to the future, this study tells us that improvement or modernization of irrigation infrastructure should be balanced between negative impacts to available water resources albeit it's significant economic contribution to the community.
Use of Multi-Objective Air Pollution Monitoring Sites and Online Air Pollution Monitoring System for Total Health Risk Assessment in Hyderabad, India
Authors: Anjaneyulu Y. , Jayakumar I. , Bindu V.  Hima , Sagareswar G. , Mukunda Rao P. V. , Rambabu N. , Ramani K.  V.
Published: October 2008

A consensus has been emerging among public health experts in developing countries that air pollution, even at current ambient levels, aggravates respiratory and cardiovascular diseases and leads to premature mortality. Recent studies have also presented well-founded theories concerning the biological mechanisms involved and the groups of people that are probably more susceptible to health effects caused or exacerbated by inhalation of ambient particulate matter (PM.). On the basis of prognostic studies carried out in Center for Environment, JNT University, Hyderabad “it has been estimated that in Hyderabad some 1,700 to 3,000 people per year die prematurely as a result of inhaling PM”. These figures reflect only the effects of acute exposure to air pollution. If the long-term effects of chronic exposure are taken into account, 10,000–15,000 people a year could die prematurely in Hyderabad. This estimate of the chronic effects is based on other studies, which are not completely comparable with the Hyderabad situation. While the study designs and analyses in these other studies may indeed be different or irrelevant to Hyderabad, the fact they were carried out in other countries is irrelevant. Taking into account these considerations, a model for total health risk assessment for the city of Hyderabad, and its state of Andhra Pradesh in India has been developed using a multi-objective air pollution monitoring network and online and real time air pollution monitoring stations. For the model studies a number of potential monitoring sites were screened for general and site-specific criteria in a geographic information system (GIS) environment that may, on a local basis, affect the representativeness of the data collected. Local features that may affect either the chemical or meteorological parameters are evaluated to assure a minimum of interference. Finally, for monitoring air pollution, an online and real-time monitoring system was designed using advanced electrochemical sensor systems (sulphur dioxide, oxides of nitrogen, carbon monoxide, hydrocarbons, ozone, mercaptans and hydrogen sulphide) and a particulate matter analyzer (total suspended particulate matter TSPM), PM2.5 and PM10). The sensor and data acquisition systems are programmed to monitor pollution levels at ½ hour durations during peak hours and at 1-hour intervals at other times. Presently, extensive statistical and numerical simulations are being carried out at our center to correlate the individuals living in the monitored areas with respiratory infections with air pollution.
Cytotoxicity and Expression of c-fos, HSP70, and GADD45/153 Proteins in Human Liver Carcinoma (HepG2) Cells Exposed to Dinitrotoluenes
Authors: Glass Konsuela , Newsome Cecilia , Tchounwou Paul
Published: October 2008

Dinitrotoluenes (DNTs) are byproducts of the explosive trinitrotoluene (TNT), and exist as a mixture of 2 to 6 isomers, with 2,4-DNT and 2,6-DNT being the most significant. The main route of human exposure at ammunition facilities is inhalation. The primary targets of DNTs toxicity are the hematopoietic system, cardiovascular system, nervous system and reproductive system. In factory workers, exposure to DNTs has been linked to many adverse health effects, including: cyanosis, vertigo, headache, metallic taste, dyspnea, weakness and lassitude, loss of appetite, nausea, and vomiting. Other symptoms including pain or parasthesia in extremities, abdominal discomfort, tremors, paralysis, chest pain, and unconsciousness have been documented. An association between DNTs exposure and increased risk of hepatocellular carcinomas and subcutaneous tumors in rats, as well as renal tumors in mice, has been established. This research was therefore designed targeting the liver to assess the cellular and molecular responses of human liver carcinoma cells following exposure to 2,4-DNT and 2,6-DNT. Cytotoxicity was evaluated using the MTT assay. Upon 48 hrs of exposure, LC50 values of 245 + 14.72μg/mL, and 300 + 5.92μg/mL were recorded for 2,6-DNT and 2,4-DNT respectively, indicating that both DNTs are moderately toxic, and 2,6-DNT is slightly more toxic to HepG2 cells than 2,4-DNT. A dose response relationship was recorded with respect to the cytotoxicity of both DNTs. Western blot analysis resulted in a significant expression (p<0.05) of the 70-kDa heat shock protein in 2,6-DNT-treated cells compared to the control cells and at the 200 μg/mL dose for 2,4-DNT. A statistically significant expression in c-fos was also observed at the 200 and 250 μg/mL treatment level for 2,4- and 2,6-DNT, respectively. However, no statistically significant expression of this protooncogene-related protein was observed at the doses of 0, 100, or 300 μg/mL or within the dose range of 0-200 μg/mL for 2,6-DNT. The 45-kDa growth arrest and damage protein was significantly expressed at the dose range of 200 – 250μg/mL for 2,6-DNT and at the dose range of 200 - 400μg/mL for 2,4-DNT. Expression of 153-kDa growth arrest and DNA damage protein was significant at the 100, 200, and 250μg/mL doses for 2,6-DNT and at the 200 μg/mL dose for 2,4-DNT. Overall, these results indicate the potential of DNTs to induce cytotoxic, proteotoxic (HSP70), and genotoxic (GADD45/153) effects, as well as oxidative stress and pro-inflammatory reactions (c-fos).
The Seasonality of Fecal Coliform Bacteria Pollution and its Influence on Closures of Shellfish Harvesting Areas in Mississippi Sound
Authors: Chigbu Paulinus , Gordon Scott , Tchounwou Paul  B.
Published: October 2008

Runoff from agricultural lands and farm animal feedlots is one of the major sources of fecal coliforms in surface waters, and fecal coliform (FC) bacteria concentrations tend to vary with season because of seasonal variations in climatic factors. However, El Niño -Southern Oscillation (ENSO) events may affect the extent and patterns of seasonality in FC levels in coastal waters. Water quality monitoring data for shellfish management collected during El Niño (1990, 1992, 1997), and La Niña (1999, 2000) years were analyzed to evaluate the extent to which these events influenced Pearl River stage, and bacterial levels, water temperature, and salinity in the western part of Mississippi Sound. Models to predict FC levels in relation to various environmental factors were also developed. In 1990, 1992 and 1997, FC geometric mean counts peaked in late winter (January/February) reaching 120 MPN (February 1990), 165 MPN (January 1992), and 86 MPN (January 1997), and then decreased considerably during spring and summer (1.2 – 19 MPN). Thereafter, FC abundance increased slightly in fall and early winter (1.9 – 24 MPN). Fecal coliform abundance during the 2000 La Niña year was much lower (1.0 – 10.3 MPN) than in 1992 (1.2 – 165 MPN), and showed no seasonal pattern from January to August, perhaps due to the relative scarcity of rainfall in 2000. In 1995 (ENSO neutral year), peak geometric mean FC count (46 MPN) was lower than during El Niño years and occurred in early spring (March). The seasonal and between year variations in FC levels determined the number of days during which the conditionally approved shellfish growing area was opened for harvesting shellfish. For example, from January to April 1997, the area was not opened for shellfish harvesting, whereas in 2000, the number of days during which the area was opened ranged from 6 - 27 (January to April) to 24 - 26 (October to December). ENSO events thus influenced the extent and timing of the peak levels of fecal coliforms in Mississippi Sound. Models consisting of one or more of the variables: Pearl River stage, water temperature, and salinity were developed to predict FC concentrations in the Sound. The model parameter(s) explained 56 to 91% of the variations in FC counts. Management of shellfish in Mississippi Sound can be improved by utilizing information on the forecasted three to seven years occurrence of ENSO events. In addition, since Pearl River stage was the most important variable predicting FC concentration in the Sound, a study of the levels and sources of FC bacteria in the river, especially the middle and lower sections, is needed for developing a management plan for reducing FC bacteria pollution in the Sound.
Environmental Exposure to Trace Elements and Prostate Cancer in Three New Zealand Ethnic Groups
Authors: Gray Marion  A. , Centeno Jose  A. , Slaney David  P. , Ejnik John   W. , Todorov Todor , Nacey John  N.
Published: October 2008

A stratified random sample of 176 men was taken from a larger community prostate study group of 1405 eligible subjects from three ethnic groups in the Wellington region of New Zealand, in order to examine ethnic differences in exposure to cadmium (Cd), selenium (Se) and zinc (Zn) and possible associations of blood levels of Cd, Se and Zn with the prevalence of elevated serum Prostate Specific Antigen (PSA); a marker of prostate cancer. Maori and Pacific Islands men were found likely to have higher Cd exposure than New Zealand Europeans through diet, occupation and smoking. However, there was no significant difference between ethnic groups in mean blood Cd levels. Pacific Islands men had significantly higher levels of blood Se than both New Zealand European men and Maori men. Maori men had significantly higher levels of blood Zn than both New Zealand European men and Pacific Islands men. A positive association was found between blood Cd and total serum PSA. Se and Zn levels were not associated with elevated PSA. Maori and Pacific Islands men have higher prostate cancer mortality rates than New Zealand European men. Ethnic differences in mortality could be contributed to by differences in rates of disease progression, influenced by exposure and/or deficiency to trace elements. However, results did not reflect a consistent ethnic trend and highlight the complexity of the risk/protective mechanisms conferred by exposure factors. Further research is needed to ascertain whether the associations found between Cd and PSA levels are biologically important or are merely factors to be considered when interpreting PSA results clinically.
Evaluation of Biochemical Changes in Chronic Arsenic Poisoning among Bangladeshi Patients
Authors: Nurun Nabi A. H. M. , Rahman M. Mahfuzur , Islam Laila N.
Published: October 2008

An estimated 40 million people in Bangladesh have been suffering from arsenic toxicity-related diseases because of drinking water contamination with high levels of naturally occurring arsenic. To evaluate the biochemical changes in chronic arsenic exposure, a total of 115 exposed subjects diagnosed as arsenicosis patients were examined and interviewed, and 120 unexposed volunteers were enrolled in this study. Drinking water, urine and peripheral blood samples were collected from all participants and analyzed. The average levels of arsenic in the drinking water and spot urine samples of the arsenicosis patients were 218.18g/L and 234.68g/L, respectively, and duration of exposure was 7.6 ± 5.2 yrs that ranged from 1-25 yrs. Prevalence of diabetes mellitus among chronic arsenic-exposed subjects was about 2.8 times higher than the unexposed subjects. The activities of alkaline phosphatase were significantly elevated in the patients, 197 U/L compared to 149 U/L in the controls, but alanine transaminase and aspartate transaminase were mostly normal. The patients had significantly lower levels of serum creatinine, 0.97 mg/dL compared to 1.15 mg/dL in the controls; but had significantly elevated levels of total protein, 84 g/L and 77 g/L respectively. The mean level of inorganic phosphate in the serum of arsenicosis patients was 6.4 mg/dL compared to 4.6 mg/dL in the unexposed subjects and the level was significantly higher, indicating substitution of the pentavalent arsenate for the phosphate ion causing underutilization of the latter. Evaluation of the lipid profiles showed while the levels of triacylglycerol were not much different, the patients had significantly lower levels of cholesterol, HDL-cholesterol and LDL-cholesterol compared to the unexposed subjects. These findings suggest significant changes in biochemical parameters in human arsenic toxicity.
The In-Home Environment and Household Health: A Cross-Sectional Study of Informal Urban Settlements in Northern México
Authors: Graham Jay  P. , Corella-Barud Verónica , Avitia-Diaz Raquel , Gurian Patrick
Published: October 2008

People living in poverty make up nearly half of the global population and a large proportion of these individuals inhabit cities, living in informal settlements. However, only limited research on in-home environmental exposures and the associated health effects in these communities is available. This research investigates the home environment in unplanned settlements of a rapidly growing city on the U.S.-México border and its impact on the health of households with children under 12 years of age. A cross-sectional design was used to assess household exposures and health outcomes at the household level. A total of 202 households were selected from two informal settlements in the peri-urban region of Ciudad Juárez, México. The following variables were significantly associated with the report of at least one household member experiencing a health outcome in a two week period. Allergies were positively associated with insecticide use inside the home (adjusted Relative Odds (RO), 2.71; 95% confidence interval (CI), 1.2-6.3). Respiratory problems were associated with households using a wood burning stove vs. a gas stove (adjusted RO, 5.64; 95% CI, 1.1-27.9). Diarrhea was negatively associated with presence of a flush toilet in the home (adjusted RO, 0.22; 95% CI,0.1-0.6). Finally, eye irritations were positively associated with indoor tobacco smoke (adjusted RO, 2.23; 95% CI, 1.1-4.5). This research highlights exposures associated with poor living conditions in informal settlements and their associations with detrimental effects on health. More efforts should be made to understand the dynamics of poor urban environments including the health effects of exposures linked with poor housing conditions.
Ozone Enhances Diesel Exhaust Particles (DEP)-Induced Interleukin-8 (IL-8) Gene Expression in Human Airway Epithelial Cells through Activation of Nuclear Factors- κB (NF-κB) and IL-6 (NF-IL6)
Authors: Kafoury Ramzi M. , Kelley James
Published: October 2008

Ozone, a highly reactive oxidant gas is a major component of photochemical smog. As an inhaled toxicant, ozone induces its adverse effects mainly on the lung. Inhalation of particulate matter has been reported to cause airway inflammation in humans and animals. Furthermore, epidemiological evidence has indicated that exposure to particulate matter (PM2.5-10), including diesel exhaust particles (DEP) has been correlated with increased acute and chronic respiratory morbidity and exacerbation of asthma. Previously, exposure to ozone or particulate matter and their effect on the lung have been addressed as separate environmental problems. Ozone and particulate matter may be chemically coupled in the ambient air. In the present study we determined whether ozone exposure enhances DEP effect on interleukin-8 (IL-8) gene expression in human airway epithelial cells. We report that ozone exposure (0.5 ppm x 1 hr) significantly increased DEP-induced IL-8 gene expression in A549 cells (117 ± 19 pg/ml, n = 6, p < 0.05) as compared to cultures treated with DEP (100 μg/ml x 4 hr) alone (31 ± 3 pg/ml, n = 6), or cultures exposed to purified air (24 ± 6 pg/ml, n = 6). The increased DEP-induced IL-8 gene expression following ozone exposure was attributed to ozone-induced increase in the activity of the transcription factors NF-κB and NF-IL6. The results of the present study indicate that ozone exposure enhances the toxicity of DEP in human airway epithelial cells by augmenting IL-8 gene expression, a potent chemoattractant of neutrophils in the lung.
Assessment of Cellular Responses to Oxidative Stress using MCF-7 Breast Cancer Cells, Black Seed (N. Sativa L.) Extracts and H2O2
Authors: Farah Ibrahim  O.
Published: October 2008

Black seed (N. Sativa L) is an oriental spice of the family Ranunculaceae that has long been rationally used as a natural medicine for treatment of many acute as well as chronic conditions including cardiovascular disease and immunological disorders. It has been used in the treatment of diabetes, hypertension, and dermatological conditions. There have been very few studies on the effects of N. Sativa as a chemoprevention of chronic diseases as well as in cancer prevention and/or therapy. Oxidative stress is a condition that underlies many acute as well as chronic conditions. The combination and role of oxidative stress and antioxidants in vivo is still a matter of conjecture. Our objective for the present study was to expose MCF-7 breast cancer cells in vitro (as a chronic disease example) to aqueous and alcohol extracts and in combination with H2O2 as an oxidative stressor. Measurement of cell survival under various concentrations and mixtures was conducted using standard cell culture techniques, exposure protocols in 96 well plates and Fluorospectrosphotometry. Following cellular growth to 90% confluencey, exposure to water (WE) and ethanol (AE) extracts of N. sativa and H2O2 was performed. Cell survival indices were calculated from percent survival using regression analysis. Results showed that the alcohol extract and its mixtures were able to influence the survival of MCF-7 cells (indices ranged from 357.15- 809.50 Bg/ml in descending potency for H2O2+AE to the mix of 3). In contrast, H2O2 alone reduced effectively the survival of MCF-7 cells and the least effective combinations in descending potency were AE+H2O2, WE+H2O2, AE+WE, and WE+AE+H2O2. Mixtures other than AE+H2O2 showed possible interactions and loss of potency. In conclusion, N. Sativa alone or in combination with oxidative stress was found to be effective (in vitro) in influencing the survival of MCF-7 breast cancer cells, unveiling promising opportunities in the field of cancer chemoprevention and/or treatment.
Dynamic Model of HIV/AIDS Population of Agra Region
Authors: Chaturvedi D.  K.
Published: October 2008

The Human Immunodeficiency Virus / Acquired Immunodeficiency syndrome (HIV/AIDS) is spreading rapidly in all regions of the world. But in India it is only 20 years old. Within this short period it has emerged as one of the most serious public health problems in the country, which greatly affect the socio-economical growth. The HIV problem is very complex and ill defined from the modeling point of view. Keeping in the view the complexities of the HIV infection and its transmission, it is difficult to make exact estimates of HIV prevalence. It is more so in the Indian context, with its typical and varied cultural characteristics, and its traditions and values with special reference to sex related risk behaviors. Therefore, it is necessary to develop a good model which will help in making exact estimates of HIV prevalence that may be used for planning HIV / AIDS prevention and control programs. In this paper Neuro-Fuzzy approach has been used to develop dynamic model of HIV population of Agra region.
Environmental Toxicology and Health Effects Associated with Methyl Parathion Exposure – A Scientific Review
Authors: Edwards Falicia  L. , Tchounwou Paul B.
Published: October 2008

Methyl parathion - MP (C8H10NO5PS) is a restricted-use pesticide that has been widely used as an agricultural insecticide. It belongs to the class of organophosphate chemicals characterized by their ability to inhibit acetylcholinesterase activity. The main route of human exposure is inhalation, but dermal contact and inadvertent ingestion can also be substantial. Populations that are susceptible to MP exposure primarily are applicators, manufacturers and individuals living near application and/or disposal sites. Exposure has also been reported as a result of illegal indoor application. MP related health effects include headaches, nausea, night-waking, diarrhea, difficulty breathing, excessive sweating and salivation, incoordination, and mental confusion. Other symptoms including behavior problems, motor skill problems and impairment of memory recall have also been reported. The primary targets of toxicity are the hematopoietic system (serum cholinesterase inhibition), the cardiovascular system (cardiovascular lesions, abnormalities in heart rate and increase in heart-to-body ratio), the reproductive system (placental morphology, fibrosis and hemorrhage, and inhibition of DNA synthesis in seminiferous tubules), and the nervous system (headache, muscle weakness, insomnia, dizziness, and impaired memory). MP is believed to not have any carcinogenic effects. In an attempt to update its toxicologic profile, we hereby provide a critical review of MP-related environmental and toxicologic effects, with a special emphasis on their potential implications for public health.
Effect of Temperature on the Survival of F-Specific RNA Coliphage, Feline Calicivirus, and Escherichia coli in Chlorinated Water
Authors: Allwood Paul  B. , Malik Yashpal  S. , Maherchandani Sunil , Hedberg Craig  W. , Goyal Sagar  M.
Published: October 2008

We compared the survival of F-specific RNA coliphage MS2, feline calicivirus, and E. coli in normal tap water and in tap water treated to an initial concentration of 50 ppm free chlorine and held at 4°C, 25°C, or 37°C for up to 28 days. Our aim was to determine which of these two organisms (coliphage or E. coli) was better at indicating norovirus survival under the conditions of the experiment. There was a relatively rapid decline of FCV and E. coli in 50 ppm chlorine treated water and both organisms were undetectable within one day irrespective of the temperature. In contrast, FRNA phage survived for 7 to 14 days in 50 ppm chlorine treated water at all temperatures. All organisms survived for 28 days in tap water at 4°C, but FCV was undetectable on day 21 and day 7 at 25°C and 37°C, respectively. Greater survival of FRNA phage compared to E. coli in 50 ppm chlorine treated water suggests that these organisms should be further investigated as indicators of norovirus in depurated shellfish, sanitized produce, and treated wastewater which are all subject to high-level chlorine treatment.
Sorption Kinetics of Escherichia coli and Salmonella sp on Two Soil Layers Associated with a Groundwater Table in Yaounde, Cameroon (Central Africa)
Authors: Nola Moïse , Njiné Thomas , Boutin Claude , Servais Pierre , Messouli Mohamed , Bidjeck Louise Marie Ngo , Monkiedje Adolphe , Zébazé Togouet Serge H. , Kemka Norbert
Published: October 2008

A laboratory study has been carried out on two soil layers (HX and HY) located above a groundwater table in Yaounde, Cameroon (Central Africa). The main purpose of this study was to assess the retention potential or sorption kinetics of Escherichia coli and Salmonella sp. on these soil layers. For both soil layers, bacterial sorption on soil particles occurred rapidly during the first 30 minutes of incubation of bacteria and soil particles in aqueous media, and increased gradually with incubation time up to 300 min. In some cases, adsorption rates fluctuated after 30 min of incubation, probably due to bacterial cell sorption to and de-sorption from soil particles. Using Freundlich isotherms, it was noted that adsorption coefficient related to adsorption capacity varied from 19 to 4026 E. coli.mg-1 of soil, and from 506 to 847 Salmonella sp.mg-1 of soil. For both bacterial species, the adsorption coefficient of layer HY (located in close proximity of the water table) was greater than that of HX (located above layer HY) and seemed to positively correlate with the pH values and N/P ratios, and to negatively correlate with the values of C/N and C/P ratios. The linearity coefficient related to adsorption intensity varied from 0.5841 to 1.0023 for E. coli, and from 0.7068 to 1.5236 for Salmonella sp. The physico-chemical characteristics of soil particles seemed to influence the sorption kinetics of bacteria on soil.
Acute Effects of Hexavalent Chromium on Survival, Oxygen Consumption, Hematological Parameters and Some Biochemical Profiles of the Indian Major Carp, Labeo rohita
Authors: Vutukuru S.  S.
Published: October 2008

An attempt has been made in the present investigation to determine the acute toxicity of hexavalent chromium and its toxicological effects on survival, physiological, hematological and biochemical parameters of the widely consumed Indian major carp, Labeo rohita. Short-term acute toxicity tests were performed adopting renewal bioassay technique (USEPA, 1975) over a period of 96h, using different concentrations of potassium dichromate to the fish and the 96 h LC50 value was found to be 111.45 mg/l (Cr+6 as 39.40 mg/l). ANOVA results showed that the normal respiratory activity of the fish was significantly affected and there is a depression in the metabolic rate at the end of 24, 48, 72 and 96h exposure. The metal also induced significant decrease (p
Assessment of the Petrochemical Industry Pollution on the Skikda Bay, Algeria
Authors: Nafissa Boutefnouchet , Bouzerna Noureddine , Chettibi Houria
Published: October 2008

The Skikda bay is located in the northern part of Algeria. The area is in contact with a petrochemical industrial complex, which raw materials and final products contaminate the surrounding areas via atmospheric pollution as well as effluents, which are dumped into seawaters. To establish the effects of these pollutants and waste disposal on the vicinity of the bay, several samples were taken at different distances along the bay and the outfall pipes of the industrial complex. Subsequently, several chemical analyses were made to analyze the concentrations of hydrocarbons, CO2, Ca+2 and Mg+2, chlorides and phosphates and the alkalinity present into the samples. Several concentrations of the above constituents are reported as a function of the different sites.
Effect of Organic Loading on Rotating Biological Contactor Efficiency
Authors: Al-Ahmady Kossay  K.
Published: October 2008

Organic loading (weight per unit time per volume) is useful for the design of rotating biological contactors (RBC) and for comparison with the other processes such as activated sludge or oxidation ponds. The present study puts emphasis on the significance of this control or design parameter because it allows direct comparison of the RBC system's performance when operated under various circumstances and with different kinds of wastewater. The results of the paper proved that, the COD removal in rotating biological contactor systems is a function of the organic loading rate. However, each of the wastewater concentration and flow rate are also influence on the system efficiency but theirs impact can be combined by the effect of organic loading. The majority of COD removal (40-85 % of the total removal depending on the organic loading applied) occurs in the first stages of the system. There is a strong correlation between the organic loading and the concentration of the suspended solids in the rotating biological contactor basin. At higher loadings higher concentrations noted. At a loading of about, (24 g/m2.d) suspended solids were 225, 125, 35, and 25 mg/L in the first, second, third and, the fourth stage respectively. To achieve an effluent quality of (BOD < 25 mg/L, COD < 60 mg/L), the system must be operated on organic loadings of about (22 gBOD/m2.d and 65 gCOD/m2.d) respectively. For nitrification process, the system must be designed to operate at organic loading of about (10 g/m2.d) or less and, the reactor or basin volume should be designed to achieve a hydraulic loading of about (40 L/m2.d) or less.
Changes in Behavior and Brain Acetylcholinesterase Activity in Mosquito Fish, Gambusia affinis in Response to the Sub-Lethal Exposure to Chlorpyrifos
Authors: Rao J.  Venkateswara , Begum Ghousia , Pallela R. , Usman P.  K. , Rao R.  Nageswara
Published: October 2008

Sub-lethal studies of chlorpyrifos, O,O-diethyl-O-(3,5,6-trichloro-2-pyridyl) phosphorothioate on mosquito fish, Gambusia affinis were carried out in vivo, for 20 days to assess the locomotor behavior in relation to bioaccumulation and interaction with a targeted enzyme, acetylcholinesterase (AChE, EC: 3.1.1.7). Fish exposed to sub-lethal concentration of 60 Ag/L (1/5 of LC50) were under stress, and reduced their locomotor behavior like distance travelled per unit time (m/min) and swimming speed (cm/sec) with respect to the length of exposure. The alteration in locomotor behavior of fish may be due to an accumulation of acetylcholine (ACh), a neurotransmitter at synaptic junctions, due to the inhibition of AChE enzyme activity (40 to 55%) in brain and also bioaccumulation of the toxicant in different parts of fish. The bioaccumulation values indicated that the accumulation of chlorpyrifos was maximum in viscera followed by head and body. The average bioconcentration values are 0.109, 0.009 and 0.004 Ag/g for viscera, head and body with depuration rates of 2.24, 1.69 and 0.39 ng/h respectively. It is evident from the results that the sub-lethal concentration [1/5 of LC50; equivalent to Lowest Observed Effect Concentration (LOEC)] of chlorpyrifos can able to alter the locomotor behavior of G. affinis in relation to the length of exposure. The findings revealed that the locomotor activity of test organism could be considered as a suitable marker to evaluate the affect of toxicant even at LOEC levels.
Second International Symposium on Recent Advances in Environmental Health Research
Authors: Mohamed Abdul K. , Tchounwou Paul B.
Published: October 2008

n/a
Comparative Study of Domoic Acid and Okadaic Acid Induced - Chromosomal Abnormalities in the CACO-2 Cell Line
Authors: Carvalho Pinto-Silva , Catia R. , Moukha Serge , Matias William  G. , Creppy Edmond  E.
Published: October 2008

Okadaic Acid (OA) the major diarrheic shellfish poisoning (DSP) toxin is known as a tumor promoter and seems likely implicated in the genesis of digestive cancer. Little is known regarding genotoxicity and carcinogenicity of Domoic Acid (DA), the major Amnesic Shellfish Poisoning (ASP) toxin. Both OA and DA occur in seafood and are of human health concerns. Micronuclei (MN) arise from abnormalities in nuclear division during mitosis due to a failure of the mitotic spindle or by complex chromosomal configurations that pose problems during anaphase. In order to evaluate the ability of okadaic acid (OA) and domoic acid (DA) to induce DNA damage we performed the micronucleus assay using the Caco-2 cell line. To discriminate between a clastogenic or aneugenic effect of OA and DA, the micronucleus assay was conducted by cytokinesis-block micronucleus assay using cytochalasin B with Giemsa staining and/or acridine orange staining, in parallel to fluorescence in situ hybridization (FISH) using a concentrated human pan-centromeric chromosome paint probe. Our results showed that OA and DA significantly increased the frequency of MN in Caco-2 cells. The MN caused by OA are found in mononucleated cells and binucleated cells, whereas those caused by DA are mainly in binucleated cells. The results of FISH analysis showed that OA induced centromere-positive micronuclei and DA increased the percentage of MN without a centromeric signal. In conclusion, both OA and DA bear mutagenic potential as revealed in Caco-2 cells by induction of MN formation. Moreover, OA induced whole chromosome loss suggesting a specific aneugenic potential, whereas DA seems simply clastogenic. At present, one cannot rule out possible DNA damage of intestinal cells if concentrations studied are reached in vivo, since this may happen with concentrations of toxins just below regulatory limits in case of frequent consumption of contaminated shell fishes.
Neuregulin 1-Βeta Cytoprotective Role in AML 12 Mouse Hepatocytes Exposed to Pentachlorophenol
Authors: Dorsey Waneene C. , Tchounwou Paul B. , Ford Byron D.
Published: October 2008

Neuregulins are a family of growth factor domain proteins that are structurally related to the epidermal growth factor. Accumulating evidence has shown that neuregulins have cyto- and neuroprotective properties in various cell types. In particular, the neuregulin-1 βeta (NRG1-β) isoform is well documented for its antiinflammatory properties in rat brain after acute stroke episodes. Pentachlorophenol (PCP) is an organochlorine compound that has been widely used as a biocide in several industrial, agricultural, and domestic applications. Previous investigations from our laboratory have demonstrated that PCP exerts both cytotoxic and mitogenic effects in human liver carcinoma (HepG2) cells, primary catfish hepatocytes and AML 12 mouse hepatocytes. We have also shown that in HepG2 cells, PCP has the ability to induce stress genes that may play a role in the molecular events leading to toxicity and tumorigenesis. In the present study, we hypothesize that NRG1-β will exert its cytoprotective effects in PCP-treated AML 12 mouse hepatocytes by its ability to suppress the toxic effects of PCP. To test this hypothesis, we performed the MTT-cell respiration assay to assess cell viability, and Western-blot analysis to assess stress-related proteins as a consequence of PCP exposure. Data obtained from 48 h-viability studies demonstrated a biphasic response; showing a dose-dependent increase in cell viability within the range of 0 to 3.87 μg/mL, and a gradual decrease within the concentration range of 7.75 to 31.0 μg/mL in concomitant treatments of NRG1-β+PCP and PCP. Cell viability percentages indicated that NRG1-β+PCPtreated cells were not significantly impaired, while PCP-treated cells were appreciably affected; suggesting that NRG1-β has the ability to suppress the toxic effects of PCP. Western Blot analysis demonstrated the potential of PCP to induce oxidative stress and inflammatory response (c-fos), growth arrest and DNA damage (GADD153), proteotoxic effects (HSP70), cell cycle arrest as consequence of DNA damage (p53), mitogenic response (cyclin-D1), and apoptosis (caspase-3). NRG1-β exposure attenuated stress-related protein expression in PCP-treated AML 12 mouse hepatocytes. Here we provide clear evidence that NRG1-β exerts cytoprotective effects in AML 12 mouse hepatocytes exposed to PCP.
Exposure to Chlorinated Biphenyls Causes Polymorphonucleocytes to Induce Progenitor Cell Toxicity in Culture
Authors: Hill Dwayne A. , Reese Carroll T. , Clarke Dwane , Martin Tanika V.
Published: October 2008

Progenitor cells (PC) are the precursors for many developmental structures and are sensitive to a variety of toxic agents including the environmental contaminants, polychlorinated biphenyls (PCBs). The mechanism(s) that contributes to the development of PCB-induced progenitor cell-related fetotoxicities are not completely understood. However, several studies have demonstrated an important role for neutrophils (polymorphonucleocytes) in the development of PCB induced toxicities. Our recent findings have indicated that conditioned medium collected from PC (CMPC) exposed to a single dose of the PCB mixture, Aroclor 1248, can activate isolated neutrophil populations. Because of our recent findings, this study was conducted to determine if conditioned medium from PC treated with a PCB mixture causes neutrophils to injure PC in culture. Isolated PC were cultured and treated with different concentrations of Aroclor 1248 for 24 hours. The resulting PC-derived conditioned media was collected and its affect on neutrophil activity was analyzed. Conditioned medium from PC treated with Aroclor 1248 was chemotactic for neutrophils. The conditioned medium from Aroclor 1248 treated-PC also stimulated neutrophils to release super oxide anion, cathepsin G and elastase into culture medium. Furthermore, the conditioned medium from Aroclor 1248 treated- PC was able to stimulate neutrophils to cause progenitor cell toxicity in co-cultures. The conditioned medium from Aroclor 1248 treated-PC was not toxic to individual neutrophil cultures or PC cultures. Moreover, the addition of a protease inhibitor to the co-cultures containing neutrophils and PC, afforded protection against neutrophil-induced cytotoxicity of PC. These data suggest that a PCB mixture can cause progenitor cells to produce a factor(s) that activates neutrophils and stimulates them to damage PC populations in culture.
Internalization of Near-Infrared Fluorescent Dyes within Isolated Leukocyte Populations
Authors: Baker Michael , Ntam Colette , Reese Carroll T. , Martin Tanika V. , Carrington Satia , Leotaub Jane , Cox Leonette , Williams Richard J. , Hill Dwayne A.
Published: October 2008

Scientists have expressed continued interest in the development of microsensor technology that can indicate toxicity that occurs within a cell after a chemical challenge. One of the more useful approaches of microsensor technology is the application of fluorescent spectroscopy to indicate early-stage injury with optimal specificity and decreased background interference. If the toxicity is detected during the early onset period of injury, then the probability for therapeutic recovery is promising. There has been increasing interest in the use of infrared (IR) and near infrared (NIR) dyes as biological microsensors due to their fluorescent spectral characteristics. Three of the most essential characteristics are the ability to minimize background interference by extraneous biological matrices, to exhibit optimal molar absorptivity and quantum yields, to maintain chronic cellular homeostasis. Therefore, the present study was developed to determine if selected NIR dyes would distribute within isolated neutrophil populations without altering normal cellular homeostasis using fluorescent wavelength analysis. The results demonstrate that selected NIR dyes undergo internalization within target cell populations while maintaining cell viability and homeostasis. In addition, these dyes demonstrate changes in absorbance and fluorescence analysis after the immune cells were challenged with a stimulant. Moreover, critical cellular functions, such as degranulation and superoxide production were not compromised by the internalization of the NIR dyes. These data suggest that selected NIR dyes can undergo intracellular uptake within neutrophil cultures without altering the normal functional capabilities of the targeted cell population.
Mercury-Induced Externalization of Phosphatidylserine and Caspase 3 Activation in Human Liver Carcinoma (HepG2) Cells
Authors: Sutton Dwayne  J. , Tchounwou Paul  B.
Published: October 2008

Apoptosis arises from the active initiation and propagation of a series of highly orchestrated specific biochemical events leading to the demise of the cell. It is a normal physiological process, which occurs during embryonic development as well as in the maintenance of tissue homeostasis. Diverse groups of molecules are involved in the apoptosis pathway and it functions as a mechanism to eliminate unwanted or irreparably damaged cells. However, inappropriate induction of apoptosis by environmental agents has broad ranging pathologic implications and has been associated with several diseases including cancer. The toxicity of several heavy metals such as mercury has been attributed to their high affinity to sulfhydryl groups of proteins and enzymes, and their ability to disrupt cell cycle progression and/or apoptosis in various tissues. The aim of this study was to assess the potential for mercury to induce early and late-stage apoptosis in human liver carcinoma (HepG2) cells. The Annexin-V and Caspase 3 assays were performed by flow cytometric analysis to determine the extent of phosphatidylserine externalization and Caspase 3 activation in mercury-treated HepG2 cells. Cells were exposed to mercury for 10 and 48 hours respectively at doses of 0, 1, 2, and 3 μg/mL based on previous cytotoxicity results in our laboratory indicating an LD50 of 3.5 ± 0.6 μg/mL for mercury in HepG2 cells. The study data indicated a dose response relationship between mercury exposure and the degree of early and late-stage apoptosis in HepG2 cells. The percentages of cells undergoing early apoptosis were 0.03 ± 0.03%, 5.19 ± 0.04%, 6.36 ± 0.04%, and 8.84 ± 0.02% for 0, 1, 2, and 3 μg/mL of mercury respectively, indicating a gradual increase in apoptotic cells with increasing doses of mercury. The percentages of Caspase 3 positive cells undergoing late apoptosis were 3.58 ± 0.03%, 17.06 ± 0.05%, 23.32 ± 0.03%, and 34.51 ± 0.01% for 0, 1, 2, and 3 μg/mL of mercury respectively, also indicating a gradual increase in Caspase positive cells with increasing doses of mercury.
The Effect of UV-B Radiation on Bufo arenarum Embryos Survival and Superoxide Dismutase Activity
Authors: Herkovits J. , D´Eramo J.  L. , Fridman O.
Published: October 2008

The exposure of Bufo arenarum embryos to 300-310 nm UV-B at a dose of 4,104 Joule/m2 resulted in 100% lethality within 24 hr while 820 Joule/m2 was the NOEC value for short-term chronic (10 days) exposure. The dose response curves show that lethal effects are proportional with the dose and achieve its highest value within 48 hr post exposure. The superoxide dismutase (SOD) activity in amphibian embryos for sublethal UV-B exposures was evaluated by means of UV-B treatments with 273 (A), 820(B), 1368(C) and 1915(D) Joule/m2 at 2 and 5 hours post irradiation. The SOD activity in units/mg protein in A, B, C and D at 2 hr after treatments were 80.72 ± 14.29, 74.5 ± 13.19, 39.5 ± 6.99 and 10.7 ± 1.89 respectively while for control embryos it was 10.88 ± 1.31. At 5 hr after treatments the SOD values were similar to those found in control embryos. The results confirm the high susceptibility of amphibian embryos to UV-B and point out that the SOD activity is enhanced by low doses of UV-B irradiation achieving significantly higher values than in control embryos at 2 hr post exposure.
Combustion-Generated Nanoparticulates in the El Paso, TX, USA / Juarez, Mexico Metroplex: Their Comparative Characterization and Potential for Adverse Health Effects
Authors: Murr L.  E. , Soto K.  F. , Garza K.  M. , Guerrero P.  A. , Martinez F. , Esquivel E.  V. , Ramirez D.  A. , Shi Y. , Bang J.  J. , Venzor, III J.
Published: October 2008

In this paper we report on the collection of fine (PM1) and ultrafine (PM0.1), or nanoparticulate, carbonaceous materials using thermophoretic precipitation onto silicon monoxide/formvar-coated 3 mm grids which were examined in the transmission electron microscope (TEM). We characterize and compare diesel particulate matter (DPM), tire particulate matter (TPM), wood burning particulate matter, and other soot (or black carbons (BC)) along with carbon nanotube and related fullerene nanoparticle aggregates in the outdoor air, as well as carbon nanotube aggregates in the indoor air; and with reference to specific gas combustion sources. These TEM investigations include detailed microstructural and microdiffraction observations and comparisons as they relate to the aggregate morphologies as well as their component (primary) nanoparticles. We have also conducted both clinical surveys regarding asthma incidence and the use of gas cooking stoves as well as random surveys by zip code throughout the city of El Paso. In addition, we report on short term (2 day) and longer term (2 week) in vitro assays for black carbon and a commercial multiwall carbon nanotube aggregate sample using a murine macrophage cell line, which demonstrate significant cytotoxicity; comparable to a chrysotile asbestos nanoparticulate reference. The multi-wall carbon nanotube aggregate material is identical to those collected in the indoor and outdoor air, and may serve as a surrogate. Taken together with the plethora of toxic responses reported for DPM, these findings prompt concerns for airborne carbonaceous nanoparticulates in general. The implications of these preliminary findings and their potential health effects, as well as directions for related studies addressing these complex issues, will also be examined.
Assessment of Public Health Risks Associated with Atmospheric Exposure to PM2.5 in Washington, DC, USA
Authors: Greene Natasha  A. , Morris Vernon  R.
Published: October 2008

In this research, we investigated the public health risks associated with atmospheric exposure to PM2.5 for different subpopulations (black, white, Hispanic, youth, adults, and elderly) in the Washington, DC area. Washington, DC has long been considered a non-healthy place to live according to the American Lung Association due to its poor air quality. This recognition clearly includes the negative PM-related human health effects within the region. Specifically, DC fine particulate matter (PM2.5) [or particulate matter with an aerodynamic diameter less than 2.5 μm] poses notable health risks to subpopulations having an annual mean value of 16.70 μg/m3 during the years 1999-2004, exceeding the EPA National Ambient Air Quality Standard (NAAQS) of 15 μg/m3. Incessant exposure to significant levels of PM has previously been linked to deleterious health effects, such as heart and lung diseases. The environmental quality and public health statistics of Washington, DC indicate the need for higher-resolution measurements of emissions, both spatially and temporally, and increased analysis of PM-related health effects. Our findings show that there are significant risks of ward-specific pediatric asthma emergency room visits (ERV). Results also illustrate lifetime excess lung cancer risks, exceeding the 1x10-6 threshold for the measured levels of particulate matter and heavy metals (chromium and arsenic) on behalf of numerous subpopulations in the DC selected wards.