Effect of coumaphos on cholinesterase activity, hematology, and biochemical blood parameters of bovines in tropical regions of Mexico

To assess the effect of coumaphos [O-(3-chloro-4-methyl-2-oxo-2H-1-benzopyran-7-yl) O,O-diethyl phosphorothioate] exposure on physiological responses during bovine production, acetylcolinesterase (AChE) and butyrylcholinesterase (BuChE) activities were measured in whole blood, erythrocytes, and plasma of healthy male steers (Bos Taurus x Bos indicus) sprayed with coumaphos at a non-lethal dose of 1 mg kg(- 1) body weight per day once every 14 (in vivo group) or 21 days (southern and central groups). Coumaphos topically administered at 1 mg/kg body weight per day to cattle under normal management practices in tropical areas produced a significant inhibition in erythrocyte (RBC) AChE and BuAChE activities when compared to baseline levels. RBC-AChE activity for the in vivo group decreased 71.3% (P < 0.05) and BuChE activity 59.1% (P < 0.05); RBC-AChE activity decreased 55.1% (P < 0.05) (southern group) and 43.4% (P < 0.05) (central group). Compared to the control specimens, steers from in vivo, southern, and central groups after 150 days of exposure had lower (P < 0.05) leukocyte count, absolute lymphocyte, erythrocyte, and platelet counts. Decreases in RBC-AChE activities correlated with decreased lymphocyte (r = 1.000, p = 0.01), erythrocyte (r = 1.000, p = 0.003), and platelet counts (r = 0.841, p = 0.036). Significantly increased BUN levels (P < 0.05) correlated with the decrease in RBC-AChE activities (r = - 0.997, p = 0.047) and with the decrease in absolute red blood cell (r = - 0.883, p = 0.020) and lymphocyte (r = - 0.825, p = 0.043) counts; increased (P < 0.05) total plasma protein levels correlated with the decrease in RBC-AChE activities (r = -0.998, p = 0.043), absolute red blood cell (r = - 0.998, p = 0.040), lymphocyte (r = - 0.893, p = 0.017), and platelet (r = -0.855, p = 0.030) counts. The physiological responses correlated with the erythrocyte acetylcholinesterase inhibition could be considered as early indicators or warning responses of bovine exposures to organophosphorus pesticides (OPs).     

Metal concentrations and potential health risk in clam (Meretrix lyrata Sowerby 1851) tissues from East Java Coast,Indonesia

Environmental Monitoring and Assessment - Global environmental changes not only contribute to the modification of global pollution transport pathways but can also alter contaminant fate within the...     

Understanding deforestation in montane and lowland forests of the Colombian Andes

Colombian Andean forests cover nine million ha. These forests provide an informative case study of mountain deforestation in South America. They are surrounded by tropical lowland forests, and they host most of the country’s human population. This study evaluates the relative importance of human and natural variables in deforestation of the Colombian Andes between 1985 and 2005 using remote sensing methods, geographic information system (GIS) technology and general linear models (GLM). The following factors affected the annual deforestation in the region positively: forced population migration, unsatisfied basic needs, economic activity, crops, pastures, illicit crops, protected areas and slope. Factors having a negative effect were tenure of small land parcels, road density, water scarcity and mean temperature. The results of this study also provide insight into the differences between the dynamics of lowland forests and those of montane forests. Montane forests had a lower annual rate of deforestation than did forests in the lowlands. Socio-economic, demographic and biophysical factors explain overall deforestation rates for the region. However, when altitude variation is taken into account, intraregional differences in the Andes become evident. Deforestation processes differ between those areas adjacent to the high Andean valleys where most of the country’s population concentrates and those areas in the tropical lowlands north, west and east of the Andean chain. Differences between lowland and montane forest dynamics are due partly to the accessibility of forests and differences in wealth and economic activities. In montane forests, deforestation is positively influenced by economic activity, the presence of protected areas and higher slopes. Deforestation in montane forests is negatively affected by tenure of small land parcels, road density, water scarcity and mean temperature. Lowland deforestation rates are more closely related to rural population, pasture percentage, crops, protected areas and temperature. Our results suggest that montane forests appear to be in a more advanced stage of colonisation and economic development, whereas lowland forests are closer to the colonisation frontier and to rapidly growing colonist populations. This study reinforces the idea that although the most common tropical drivers of deforestation are found in the Andes, these drivers operate differently when intraregional differences are considered.     

National and regional determinants of tropical deforestation in Colombia

Global tropical deforestation continues to occur at high rates despite political attention. National-level forest baselines are being established all over the world to guide the implementation of several policy mechanisms. However, identifying the direct and indirect drivers of deforestation and understanding the complexity of their interlinkages are often difficult. We first analyzed deforestation between 1990 and 2005 at the national level and found an annual deforestation rate of 0.62 %. Next, we performed separate analyses for four natural regions in Colombia and found annual deforestation rates between 0.42 and 1.92 %. Using general linear models, we identified several direct causes and underlying factors influencing deforestation at the national level: rural population density, cattle, protected areas, and slope. Significant differences in deforestation rates and causes were found across regions. In the Caribbean region, drivers of loss are urban population, unsatisfied basic needs, slope, and precipitation and four land use variables (illicit crops, pastures, cattle, and fires). In the Orinoco region, crops are the main driver of forest loss, and in the Amazonian region, deforestation is primarily due to fires related to the colonization front. Policy mechanisms will have to take into account regional patterns to successfully balance development and forest preservation in Colombia.     

Measurement of pollution levels of organochlorine and organophosphorus pesticides in water, soil, sediment, and shrimp to identify possible impacts on shrimp production at Jiquilisco Bay

This study aims to identify levels of several organochlorine and organophosphorus compounds in shrimp-raising areas of coastal El Salvador, to assess potential impacts on shrimp growth and survival that hamper the sustainability of aquaculture in the region. The paper reports the current levels of γ-HCH, 4,4'-DDT, 4,4'-DDE, 4,4'-DDD, endrin, dieldrin, heptachlor, parathion, methyl parathion, and etoprophos in soils (depth 20 cm), sediments (depth 5 cm), shrimp (Penaeus sp.), and water of three rearing ponds and also in the sediment (depth 5 cm) and water surrounding those ponds in Jiquilisco Bay. Sampling was carried out during the dry (January-March) and rainy (June-August) seasons of 2008. The presence of pesticides in the samples of water, shrimp, and sediment at shrimp ponds was not detected in either season; however, in soil samples (depth 20 cm) taken from these ponds, heptachlor, endrin, dieldrin, 4,4'-DDD, and 4,4'-DDT were identified at concentrations below the method limit of quantification (LOQ), and 4,4'-DDE was found in a concentration falling in the range from 3.85 to 19.61 ng/g. In samples of water taken at the bay water intakes to the rearing ponds, we observed dieldrin concentrations in the range between 0.085 ng/mL and 0.182 ng/mL during the dry season. In the samples of sediments taken in the surrounding areas of shrimp ponds, we found-for both seasons-that in 60 % of the samples, 4,4'-DDE was present in concentrations ranging from 3.75 ng/g to 30.97 ng/g. Additionally, in the rainy season, we observed heptachlor in sediment at concentrations below the method quantification limit. It was concluded that organochlorine compounds from pesticides are still present in Jiquilisco Bay, trapped in deep sediment, even though they have been banned since the 1980s. These were not detected in shrimp tissue, surface water, and shallow sediment in rearing ponds, and hence, we do not believe their presence has any major impact on shrimp production in sampled areas.     

Impacts of multidisciplinary actions on environmental lead exposure in Uruguay

Environmental lead contamination in Uruguay became a matter of public concern in 2001, when cases of children with blood lead levels (BLL) higher than 20 μg/dl appeared in some low-income neighborhoods of Montevideo, being 10 μg/dl the intervention reference BLL. The aim of this paper is to show the results of multidisciplinary actions taken by decisions makers in social, environmental and healthcare aspects, to minimize lead exposure risks. We evaluated changes in blood lead levels of different children and non-exposed adult populations before and after the actions were taken, from 2001 on. For children populations and non-exposed adults, we found a significant decrease of almost 50% in BLL compared with studies done before the actions were taken. The main action to consider was the phasing out process of leaded gasoline in our country among other. We conclude that the integration of inter and multidisciplinary actions promoted was of high impact on the population, bringing about a public sensitization and growing awareness of the lead environmental risks.     

Effect of coumaphos on cholinesterase activity,hematology, and biochemical blood parameters of bovines in tropical regions of Mexico

To assess the effect of coumaphos [O-(3-chloro-4-methyl-2-oxo-2H-1-benzopyran-7-yl) O,O-diethyl phosphorothioate] exposure on physiological responses during bovine production, acetylcolinesterase (AChE) and butyrylcholinesterase (BuChE) activities were measured in whole blood, erythrocytes, and plasma of healthy male steers (Bos Taurus x Bos indicus) sprayed with coumaphos at a non-lethal dose of 1 mg kg^{? 1} body weight per day once every 14 (in vivo group) or 21 days (southern and central groups). Coumaphos topically administered at 1 mg/kg body weight per day to cattle under normal management practices in tropical areas produced a significant inhibition in erythrocyte (RBC) AChE and BuAChE activities when compared to baseline levels. RBC-AChE activity for the in vivo group decreased 71.3% (P < 0.05) and BuChE activity 59.1% (P < 0.05); RBC-AChE activity decreased 55.1% (P < 0.05) (southern group) and 43.4% (P < 0.05) (central group). Compared to the control specimens, steers from in vivo, southern, and central groups after 150 days of exposure had lower (P < 0.05) leukocyte count, absolute lymphocyte, erythrocyte, and platelet counts. Decreases in RBC-AChE activities correlated with decreased lymphocyte (r = 1.000, p = 0.01), erythrocyte (r = 1.000, p = 0.003), and platelet counts (r = 0.841, p = 0.036). Significantly increased BUN levels (P < 0.05) correlated with the decrease in RBC-AChE activities (r = ? 0.997, p = 0.047) and with the decrease in absolute red blood cell (r = ? 0.883, p = 0.020) and lymphocyte (r = ? 0.825, p = 0.043) counts; increased (P < 0.05) total plasma protein levels correlated with the decrease in RBC-AChE activities (r = ?0.998, p = 0.043), absolute red blood cell (r = ? 0.998, p = 0.040), lymphocyte (r = ? 0.893, p = 0.017), and platelet (r = -0.855, p = 0.030) counts. The physiological responses correlated with the erythrocyte acetylcholinesterase inhibition could be considered as early indicators or warning responses of bovine exposures to organophosphorus pesticides (OPs).     

Effectiveness of protected areas in the Colombian Andes: deforestation, fire and land-use changes

Protected areas (PAs) are one of the most common conservation strategies to halt biodiversity loss. However, little is known about their current effectiveness and how they could behave under projected scenarios of change, especially in the mountain ecosystems of the Andean region. In this study, we assess the role of protected areas against deforestation and fire incidence in the Colombian Andes and how variables associated with biophysical and context drivers such as the size, year of creation and geographic location of the PAs affect their effectiveness. For the long-term, we have addressed the question of how effective these areas will be under three different scenarios of change for the period between 2020 and 2050, including a reference scenario and two scenarios of increasing pastureland and croplands. The results obtained indicated that both deforestation and fire levels were significantly lower inside protected areas than outside their borders. Concerning variables affecting deforestation and fire, only the type of ecosystem affected these processes in this study. The magnitude of forest loss was different between the analysed scenarios and depended on the location of the PAs. The PAs located in the Western Mountain Range presented the largest values of deforestation but the lowest number of fire incidences. This finding could be related to the presence of processes other than fire, such as illegal logging or selective extraction. The largest losses are expected in the PAs associated with the Eastern and Central mountain ranges, whereas the Western Mountain range will have the lowest loss. We conclude that although the Andes Mountains are a highly transformed and dynamic region, the current PAs have been effective barriers for deforestation and fire. However, the creation of new areas and the maintenance of the current PAs should take into account the interaction with the surrounding population, especially in those areas that are more sensitive to change.     

Brazilian free-tailed bats as insect pest regulators in transgenic and conventional cotton crops.

During the past 12000 years agricultural systems have transitioned from natural habitats to conventional agricultural regions and recently to large areas of genetically engineered (GE) croplands. This GE revolution occurred for cotton in a span of slightly more than a decade during which a switch occurred in major cotton production areas from growing 100% conventional cotton to an environment in which 95% transgenics are grown. Ecological interactions between GE targeted insects and other insectivorous insects have been investigated. However, the relationships between ecological functions (such as herbivory and ecosystem transport) and agronomic benefits of avian or mammalian insectivores in the transgenic environment generally remain unclear, although the importance of some agricultural pest management services provided by insectivorous species such as the Brazilian free-tailed bat, Tadarida brasiliensis, have been recognized. We developed a dynamic model to predict regional-scale ecological functions in agricultural food webs by using the indicators of insect pest herbivory measured by cotton boll damage and insect emigration from cotton. In the south-central Texas Winter Garden agricultural region we find that the process of insectivory by bats has a considerable impact on both the ecology and valuation of harvest in Bacillus thuringiensis (Bt) transgenic and nontransgenic cotton crops. Predation on agricultural pests by insectivorous bats may enhance the economic value of agricultural systems by reducing the frequency of required spraying and delaying the ultimate need for new pesticides. In the Winter Garden region, the presence of large numbers of insectivorous bats yields a regional summer dispersion of adult pest insects from Bt cotton that is considerably reduced from the moth emigration when bats are absent in either transgenic or non-transgenic crops. This regional decrease of pest numbers impacts insect herbivory on a transcontinental scale. With a few exceptions, we find that the agronomics of both Bt and conventional cotton production is more profitable when large numbers of insectivorous bats are present.