Inhibition of Acetylcholinesterase Activity in the Golden Apple Snail (Pomacea canaliculata Lamarck) Exposed to Chlorpyrifos, Dichlorvos or Carbaryl Insecticides

Long-acting inhibitors of acetylcholinesterase (AChE) are used in large amounts as insecticides in agriculture, and are thereby introduced into the evironment. By incubating golden apple snails in chlorpyrifos, dichlorvos, or carbaryl, we determined the LD50’s to 3.7, 4.5 and 49 µM, respectively. AChE activities were measured in several organs; the highest activity was found in the gills. Following incubation in either of the three insecticides, the ED50’s for AChE inhibition in the gills were 0.37 µM, 0.22 µM, and 14 µM, respectively; there were no sex differences, but AChE inhibition was more marked in larger snails than in smaller ones, and incubation at 32 °C brought about a higher AChE inhibition than at 27 °C. The time course of AChE inhibition was studied in snails incubated at ED50 with either of the inhibitors. There was a 50% enzyme inhibition after about 6 min, 5 min, and 7 min, respectively. After 96 h incubation, enzyme inhibiton reached about 90% in all three groups. Following this exposure to inhibitor, the snails were transferred to fresh water; after 30 days there was virtually no recovery of AChE actvity in the snails exposed to chlorpyrifos or dichlorovos, whereas about 20% was recovered in snails exposed to carbaryl

Preliminary Screening a Potential AChE Inhibitor in Thai Golden Shower (Leguminosae mimosoideae) Extracts

Pesticides are used to control pests of agriculture products in many countries including Thailand. Since they can exert harmful effects not only on target pests but also on other useful organisms, alternative agents are investigated. We studied the capacity of the Thai golden shower (Leguminosae mimosoideae) extracts (root and pod) to inhibit acetyl cholinestarese (AChE) in the golden apple snail (Pomacea canaliculata) as a pest representative. The results showed that the percentage of AChE inhibition increased with increasing in exposure times. The inhibition expressed the same trend in both male and female apple snails. AChE inhibition was higher in extracts from root than from pod. Chromatography-Mass Spectrometer (GC-MS) chromatograms demonstrated anthraquinone, an AChE inhibitor, in extracts of golden shower. Our data indicate that a potential AChE inhibitor tends to accumulate more in the root part than in the pod

Efficiency of methods to investigate PAHs exposure in fish

The aim of this study was to compare the efficiency of two methods for assessing PAH exposure in fish: measurement of the fluorescence intensity of PAH metabolites in bile (by Fixed Wavelength Fluorescence, FF), and determination of Ethoxyresourfin-O-Deethylase (EROD) activity in fish liver. In addition, we studied oxygen consumption rate and osmoregulation capacity, which are also used as indicators for PAH contamination in water. Nile tilapia (Oreochromis niloticus) was exposed to benzene, fluorene, anthracene, chrysene, and benzo[a]pyrene at non-lethal concentrations. The results showed that the fluorescence intensity, EROD activity, and oxygen consumption rate were significantly increased with increased exposure times and PAH concentrations. The maximum values were reached after 16 days' exposure. The measurement of fluorescence intensity of PAH metabolites by FF technique was more sensitive than determination of EROD activity; therefore the FF technique should be preferred in the study of long term exposure. However, the measurement of fluorescence intensity, EROD activity, and oxygen consumption rate can all be used to monitor PAH contamination in water

Urban coral reefs: Degradation and resilience of hard coral assemblages in coastal cities of East and Southeast Asia

© 2018 The Author(s) Given predicted increases in urbanization in tropical and subtropical regions, understanding the processes shaping urban coral reefs may be essential for anticipating future conservation challenges. We used a case study approach to identify unifying patterns of urban coral reefs and clarify the effects of urbanization on hard coral assemblages. Data were compiled from 11 cities throughout East and Southeast Asia, with particular focus on Singapore, Jakarta, Hong Kong, and Naha (Okinawa). Our review highlights several key characteristics of urban coral reefs, including “reef compression” (a decline in bathymetric range with increasing turbidity and decreasing water clarity over time and relative to shore), dominance by domed coral growth forms and low reef complexity, variable city-specific inshore-offshore gradients, early declines in coral cover with recent fluctuating periods of acute impacts and rapid recovery, and colonization of urban infrastructure by hard corals. We present hypotheses for urban reef community dynamics and discuss potential of ecological engineering for corals in urban areas

Exposure Assessment for Biomass Smoke among “Rice in the Bamboo”

This study focuses on comparing different measurements of biomass smoke exposure among “rice in the bamboo” producing workers in Thailand. Repeated measurements of PM2.5, levoglucosan, and urinary methoxyphenols concentrations from a subsample of the exposed workers were analyzed. The analyses of variance components and variance ratios were calculated using ANOVA, and t-tests comparison on the before and after exposure levels. The results of the study revealed that levoglucosan measurement in the personal breathing zone was the most suitable measure of exposure to biomass smoke in this group of population. Urinary methoxyphenols offered no great advantage over environmental monitoring in this study. PM2.5 did poorly for a choice of biomass smoke measurement

Reef fish and coral assemblages at Maptaput, Rayong Province

This study describes the structure of coral and fish assemblages of a group of small islands and pinnacles in the vicinity of Maptaput deep sea port, Rayong Province, Thailand during 2002. The coral and fish assemblages at Saket Island and nearby pinnacle, Hin-Yai, which are located less than 1 km from the deep sea port, had changed. Living coral cover in 2002 was 8% at Hin-Yai and 4% at Saket Island which decreased from 33% and 64%, respectively in the previous report in 1992. Numbers of coral species at Saket Island decreased from 41 species to 13 species. Acropora spp. that previously dominated the area had nearly disappeared. For fishes, a total of 40 species were found in 2002 the numbers decreased to only 6 species at Saket Island and 36 species at Hin-Yai. Fishes that dominated the area are small pomacentrids. After 1997, the conditions of coral and fish assemblages at Saket Island and Hin-Yai had markedly changed, whereas, the conditions found in the nearby area are much better. Sediment load from port construction was the primary cause of the degradation. This should indicate the adverse effect of sedimentation on coral and reef fish assemblages at Maptaput. Coral communities developed on rock pinnacles west of Maptaput deep-sea port are reported and described herein for the first time

Water pollution and habitat degradation in the Gulf of Thailand

The Gulf of Thailand has been a major marine resource for Thai people for a long time. However, recent industrialization and community development have exerted considerable stress on the marine environments and provoked habitat degradation. The following pollution problems in the Gulf have been prioritized and are discussed in details: (1) Untreated municipal and industrial waste water are considered to be the most serious problems of the country due to limited waste water treatment facilities in the area. (2) Eutrophication is an emerging problem in the gulf of Thailand. Fortunately, the major species of phytoplankton that have been reported as the cause of red tide phenomena were non-toxic species such as Noctiluca sp. and Trichodesmium sp. (3) Few problems have been documented from trace metals contamination in the Gulf of Thailand and public health threat from seafood contamination does not appear to be significant yet. (4) Petroleum hydrocarbon residue contamination is not a problem, although a few spills from small oil tankers have been recorded. A rapid decrease in mangrove forest, coral reefs, and fisheries resources due to mismanagement is also discussed

Health Risk Assessment and DNA Damage of Volatile Organic Compounds in Car Painting Houses

Car painters who work near volatile organic compounds (VOCs) sources, including paints, solvents and painting processes may be exposed to highly elevated VOCs levels. This study investigates air samples from car painting houses in Thailand to evaluate the health risks following inhalation exposure. Personal air samplings were obtained at nine garages in Phitsanulok, Thailand from June to September 2012. The concentrations of benzene, toluene, ethylbenzene, xylenes, and styrene in the air workplaces were significantly higher than in a control group of office workers (p < 0.05). Toluene, xylene and ethylbenzene were the most abundant species. However, all VOCs in these air samples were lower than TWA limit of Thailand and the OSHA standard. The lifetime cancer and non-cancer risks for the workers exposed to VOCs were also assessed. The average lifetime cancer risk was 41.0 (38.2-47.2) per million, which is in the acceptable risk. The average lifetime non-cancer risk, the HI, was 0.962 (0.643-1.397), which is well below the reference hazard level. Urine samples, collected after 8-h work periods which were analyzed for VOCs metabolites, including t,t muconic acid, hippuric acid, mandelic acid and m-hippuric acid, demonstrate that the average levels of metabolites in car painters and in controls were close. All VOCs metabolites in urine samples were lower than BEI of ACGIH standard. Blood samples, collected after 8-h work periods which were analyzed by single cell gel electrophoresis (comet) assay. The DNA damage, assessed by tail moment, demonstrates that the average of tail moment in car painters were significantly higher than in the controls (p < 0.05)

Cytochrome P450 1A activity in liver and fixed wavelength fluorescence detection of polycyclic aromatic hydrocarbons in the bile of tongue-fish (Cynoglossus acrolepidotus, Bleeker) in relation to petroleum hydrocarbons in the eastern Gulf of Thailand

Abstract: This investigation was conducted in an area of oil spill along the east coast of Thailand to examine the relations among cytochrome P450 1A activity in liver and PAHs in the bile of the tonguefish and petroleum hydrocarbons in the sediments. PAH sediment concentrations in the reference and oil spill areas were 5.03 + 0.42 and 0.21 + 0.043 µg -1 dry weight respectively. Cytochrome activity in fish liver from oil spill area was 45.40 + 3.50 pmoles/ min/mg protein, almost threefold higher than that from the reference sites. Flourescense detection in bile metabolites at the oil spill area, 69.8 + 9.9 flourescense unit was significantly higher than that at the reference sites, 22.9 + 5.5 and 22.2 + 3.5 fluorescence unit. A strong correlation was found among cytochrome P450 1A activity in liver, PAH of bile metabolites and petroleum hydrocarbons. Both cytochrome and bile metabolites activity decreased seaward varying to the distance from the oil polluted area. We concluded that both detections in tonguefish can be regarded as a complementary biomarkers for the exposure of PAHs in tropical marine environments