Preliminary investigation of chloramphenicol in fish, water and sediment from freshwater aquaculture pond

Analytical methods of chloramphenicol in the aquaculture environment have been developed using high-performance liquid chromatography and liquid chromatography-tandem mass spectrometry. The contents of chloramphenicol were determined using high-performance liquid chromatography for sediment and liquid chromatography-tandem mass spectrometry for fish and water collected from a freshwater aquaculture pond in China. Chloramphenicol in the water and sediment were 112.3 ng/L and 0.1957 mg/kg, respectively. The chloramphenicol residues in 3 kinds of fish, including carp, chub and grass carp were different. Only the muscle and head of grass carp were under the minimum required performance limit [0.3 micro g/kg] and were safe to eat. The chloramphenicol in other tissues of grass carp, carp and chub exceeded the minimum required performance limit. The highest content of chloramphenicol was in the branchia of carp and the lowest was in the head of grass carp. The results showed the chloramphenicol in the aquaculture environment was serious, although the government of China had banned the use of chloramphenicol in aquaculture a few years ago

Chemical speciation of fine particle bound trace metals

This study reported quantifications of fine particle bound trace metals and their potential health risks for residents in Guangzhou, a rapidly developing and most populated city in South China. The fine particle samples were collected from October 29th. to November 8th. of 2006 at two different elevations in a mainly residential area and analyzed for the total concentration of aluminum, iron, zinc, lead, manganese, copper, arsenic, chromium, nickel, cadmium, molybdenum and cobalt. Results showed that the fine particle concentrations ranged from 95.8 micro g/m[3]to 194.7 micro g/m[3] at the ground and 83.3-190.0 micro g/m[3] on the roof, which were much higher than the 24 h fine particle standard [35 micro g/m[3]] recommended by USEPA. The total concentrations of zinc, lead, arsenic, chromium and cadmium in fine particle were 504.8, 201.6, 24.3, 7.7 and 4.4 ng/m[3], respectively, which were comparable to other major cities of China, but much higher than major cities outside of China. A sequential extraction procedure was used to fractionate these fine particle bound metals into four different fractions. Results indicated that most toxic metals were mainly distributed in bioavailable fractions. For instance, about 91% of cadmium, 85% of lead and 74% of arsenic were in bioavailable forms. Risk calculations with a simple exposure assessment model showed that the cancer risks of the bioavailable fractions of arsenic, chromium and cadmium were 3 to 33 times greater than usual goal, indicating serious health risks to the residents in this urban area

Remediation of soil co-contaminated with pyrene and cadmium by growing maize [Zea mays L.]

Sites co-contaminated with organic and metal pollutants are common and considered to be a more complex problem as the two components often causes a synergistic effect on cytotoxicity. Phytoremediation has been proposed as a cost-effective technology for treating heavy metal or organic contamination and may be suitable for remediation of co-contaminated soil. This study investigated theconcurrent removal of pyrene and cadmium in co-contaminated soil by growing maize in a pot experiment. At the end of 60 day culture, pyrene in spiked soil diminished significantly, accounting for 21-31% of the initial extractable concentration in unplanted soil and 12-27% in planted soil. With the increment of cadmium level, the residual pyrene both in unplanted and planted soil tended to increase. Although the presence of cadmium increased the accumulation of pyrene in maize, plant accumulation only account for less than 0.30% of the total amount of the dissipated pyrene in vegetated soils. It implied that plant-promoted microbial biodegradation was the predominant contribution to the plant-enhanced dissipation of pyrene in co-contaminated soil. Unlike pyrene, heavy metal cadmium cannot be degraded. It was observed that maize can concurrently removed about on the average 0.70% of the total cadmium amount in soil by plant uptake, but Cd phytoextraction would be inhibited under contamination of pyrene. Maize CT38 can normally grow in the co-contaminated soil with high level Cd and pyrene and can effectively remedy the sites co-contaminated with these two types of contamination, which suggest the possibility of simultaneous phytoremediation of two different contaminant types