Eugenol diffusion coefficient and its potential to control Sitophilus zeamais in rice.

Given the insecticidal potential of eugenol as a fumigant, this work aimed to determine the diffusion coefficient of eugenol emanating from a pure standard solution (99%), as well as from clove essential oil (Eugenia caryophillata Thunb. (Myrtaceae)) through rice grain; to chemically analyse the volatile composition of commercially available eugenol and clove essential oil; and to evaluate the mortality of Sitophilus zeamais Motschulsky (Coleoptera: curculionidae) after exposure to eugenol inside a test chamber filled with rice. The solid phase microextraction method of extracting and quantifying eugenol by gas chromatography presented a good analytical response for the quantification of the analyte. There was no significant difference between the diffusion coefficient of eugenol diffusing from pure eugenol or from clove essential oil. The diffusion coefficient of eugenol through rice with the conditions herein adopted is 1.09 × 10-3 cm2 s-1. The characterization of clove essential oil confirmed the presence of eugenol as its major component (74.25%). A difference was observed in the composition of the distinct phases evaluated. The exposure of adult S. zeamais to diffused eugenol from pure eugenol over seven days resulted in significantly higher mortality rates (~37%) than eugenol diffused from clove essential oil (~11%). No differences in mortality rates were observed in individuals placed at different positions inside the test chamber during eugenol fumigation.

Effect of application rate on fumigant degradation in five agricultural soils.

Soil fumigation is an important pest management tool for many high value crops. To address the knowledge gap of how fumigant concentration in soil impacts dissipation, and thereby efficacy, this research determined the degradation characteristics of four fumigants as affected by application rate. Laboratory incubation experiments were conducted to determine degradation rates of 1,3-dichloropropene (both cis- and trans isomers), chloropicrin (CP), dimethyl disulfide (DMDS), and methyl iodide (MeI) in five agricultural soils. Fitted to pseudo first-order kinetics, the degradation rate constant (k) of CP, DMDS, and MeI decreased significantly as application rate increased while the 1,3-D isomers were the least affected by rate. Half-lives increased 12, 17, and 6-fold for CP, DMDS, and MeI, respectively, from the lowest to the highest application rate. At low application rates, the degradation rate of all fumigants in the Hueneme sandy loam soil was reduced by 50-95% in sterilized soil compared to the biologically active controls. However, this difference became much smaller or disappeared at high application rates indicating that biodegradation dominates at low concentrations but chemical degradation is more important at high concentrations. When co-applied, CP degradation was enhanced with biodegradation remained above 50%, while 1,3-D degradation was either reduced or not changed. Among the fumigants tested, the relative importance of biodegradation was DMDS>CP>MeI>1,3-D. These results are useful for determining effective fumigation rates and for informing regulatory decisions on emission controls under different fumigation scenarios.

Efficacy of fumigation with Trans-cinnamaldehyde and eugenol in reducing Salmonella enterica serovar Enteritidis on embryonated egg shells.

This study investigated the efficacy of two GRAS (generally regarded as safe)-status, plant-derived antimicrobials (PDAs), namely trans-cinnamaldehyde (TC) and eugenol (EUG) applied as a fumigation treatment in reducing SE on embryonated egg shells. Egg shells of day-old embryonated eggs were spot inoculated with a 4-strain mixture of SE (∼6.5 log CFU/egg) and subjected to fumigation with the aforementioned PDAs (0 or 1% concentration) for 20 minutes in a hatching incubator. SE on the shell and embryo was enumerated on days 1, 3, 6, 9, 13, 16 and 18. On day 13, the eggs were re-inoculated, followed by fumigation treatment for 20 minutes. Since the two PDAs were dissolved in ethanol (final concentration 0.04%), eggs fumigated with ethanol were included as a control.Approximately 6 log CFU/egg of SE were recovered from the shell of untreated, inoculated eggs on days 1 and 13. The fumigation of embryonated egg shells with the two PDAs was more effective in reducing SE on the shell and embryo compared to controls (P < 0.05). On day 18, the eggs fumigated with ethanol were SE positive on the shell, whereas no pathogen was detected on eggs subjected to fumigation with TC and EUG. Similarly, although the embryos of eggs subjected to fumigation with ethanol yielded 1 log CFU/egg of SE on day 18, the embryos of TC and EUG treated eggs were devoid of the pathogen. This study demonstrated that TC and EUG dissolved in 0.04% ethanol could potentially be used as a fumigation treatment for reducing SE on embryonated egg shell, however, quality traits of eggs, including the hatchability need to be ascertained.

The occurrence of bromide in herbal drugs: is there a need for a Ph. Eur. limit?

This contribution provides an overview on the current legal requirements regarding limits for bromide and presents data on the actual bromide burden of commonly used herbal drugs. Evaluation of an extensive data base shows that results exceeding the limit of 50 mg/kg are found in specific plants which take up bromide to a high extent from the environment. Thus, positive findings of bromide in herbal drugs do not necessarily serve as a proof for methyl bromide treatment. Taking into account the ADI recommended by EMA and WHO, there are no toxicological concerns with regard to the intake of herbal teas, extracts or comminuted herbal drugs at therapeutic doses. Furthermore, the use of methyl bromide and other fumigants must be documented within the batch documentation. If stated in the batch documentation that no fumigation was carried out, it is not necessary to perform the test on bromide. In cases of a particular suspect and if toxicological concerns exist, additional testing can be performed in accordance with the limits set by Regulation (EC) No. 396/2005. For the above reasons, information obtained by performing the test on bromide is not significant for the assessment of quality. Therefore, it seems no longer necessary to maintain bromide in Ph. Eur. general chapter 2.8.13. Pesticide residues and it is recommended to delete it from Table 2.8.13.-1.

Development of a rapid resolution liquid chromatographic method combined with chemometrics for quality control of Angelicae dahuricae radix.

INTRODUCTION: Angelicae dahuricae radix (Baizhi) is a widely used traditional Chinese medicine, for which the traditional processing method has been sun-drying after harvesting. In recent years this method has been replaced by sulphur-fumigation for the sake of improving its appearance and pest control. Correct identification of sulphur-fumigated Baizhi and rapid finding of appropriate chemical markers for the quality control of Baizhi are of very great importance. OBJECTIVE: To develop a rapid and efficient method of rapid resolution liquid chromatography (RRLC) combined with chemometrics for discriminating sulphur-fumigated Baizhi and controlling its quality. METHODOLOGY: The samples were separated on a Zorbax SB-C18-column with a gradient elution programme using methanol and water. The optimal RRLC method was validated in terms of linearity, precision, stability and recovery test. In addition, hierarchical clustering analysis (HCA) and principle component analysis (PCA) were applied to differentiate the different samples. RESULTS: All the constituents were well separated within 18 min. The results of chemical fingerprinting and quantitative analysis showed that the sulphur-fumigated method obviously destroyed the phytochemical profiles of Baizhi. Moreover, the sun-dried and sulphur-fumigated Baizhi could be clearly separated by HCA and PCA, and the critical markers such as oxypeucedanin and imperatorin accountable for such differences were ultimately screened out. CONCLUSION: This study revealed that sulphur-fumigation is an inappropriate approach for processing crude drugs and should be prohibited, and that the proposed RRLC method combined with chemometrics demonstrated an efficient strategy for quality control of Baizhi.

Assessment of ozone effects on local rice cultivar by portable ozone fumigation system in Hanoi, Vietnam.

This study examined the effects of troposphere ozone (O3) on rice by developing a portable ozone fumigation system and applied to the field in Hanoi, Vietnam. The system was nearly identical to the open top chamber but designed to easily and cheaply assess the O3 sensitivity of local agricultural crops in the actual field. The rice (Oryza sativa L.) was exposed to ozone during the flowering stage at peri-urban experimental site of Hanoi. The fumigation protocols covered five different levels, namely; non-filtered air (ambient) as the control treatment, 32, 62, 85 and 113 ppb in 7-h mean. It was found that observed impacts corresponded well to similar open-top chamber studies in other Asian countries. The methodology and the system left a large room for improvement and called for very careful interpretation and pre-conditions (e.g. low ambient O3 concentration). However, the portable O3 exposure in the field might open a door to the less developed countries to implement the phytotoxic risk assessment of the local agricultural species.

Effect of phosphine dose on sorption in wheat.

BACKGROUND: In spite of the extensive use of phosphine fumigation around the world to control insects in stored grain, and the knowledge that grain sorbs phosphine, the effect of concentration on sorption has not been quantified. A laboratory study was undertaken, therefore, to investigate the effect of phosphine dose on sorption in wheat. Wheat was added to glass flasks to achieve filling ratios of 0.25-0.95, and the flasks were sealed and injected with phosphine at 0.1-1.5 mg L(-1) based on flask volume. Phosphine concentration was monitored for 8 days at 25 degrees C and 55% RH. RESULTS: When sorption occurred, phosphine concentration declined with time and was approximately first order, i.e. the data fitted an exponential decay equation. Percentage sorption per day was directly proportional to filling ratio, and was negatively correlated with dose for any given filling ratio. Based on the results, a tenfold increase in dose would result in a halving of the sorption constant and the percentage daily loss. Wheat was less sorptive if it was fumigated for a second time. CONCLUSIONS: The results have implications for the use of phosphine for control of insects in stored wheat. This study shows that dose is a factor that must be considered when trying to understand the impact of sorption on phosphine concentration, and that there appears to be a limit to the capacity of wheat to sorb phosphine.

Factors influencing the effectiveness of malaria control in Bioko Island, equatorial Guinea.

The Bioko Island Malaria Control Project (BIMCP) has carried out intensive interventions since early 2004 to reduce malaria transmission through indoor residual spraying (IRS) and case management. Annual parasite prevalence surveys have been carried out to monitor the effectiveness of the program. Significant overall reductions in prevalence of infection have been observed, with 42% fewer infections occurring in 2006 compared with baseline. Nevertheless, there is evidence of considerable heterogeneity in impact of the intervention. Prevalence of infection was significantly associated with spray status of the child's house, spray coverage with effective insecticide of the neighborhood of the house, bed net use, and time elapsed since last spray. Careful scheduling of spray coverage is therefore essential to maximize the effectiveness of IRS and to ensure consistent reductions in parasite prevalence. This can only be achieved if comprehensive monitoring systems are in place for both the management and evaluation of the intervention.

The relation between phosphine sorption and terminal gas concentrations in successful fumigation of food commodities.

Owing to increased tolerance and the development of resistance in stored product insects to the fumigant phosphine, in recent years there has been a shift in the target terminal concentration from 100 ppm (100 mL m(-3)) to a higher level of 1000 ppm to achieve 100% insect mortality in 7 day commodity treatments. Therefore, there is a need to investigate whether the revised target concentration could be achieved for food commodities fumigated with phosphine at the standard dose of 2 g m(-3) for 7 days under airtight conditions at > or = 25 degrees C. When different types of food commodity (total 74) were fumigated (300 g per replicate) with phosphine at 2 g m(-3) for 7 days, the terminal gas concentrations in the free space of the commodities varied from 0 to > 2000 ppm. In chambers containing no substrate, a 1417 ppm concentration was recorded. Paddy rice, most of the oilseeds, shelled tree nuts, butter beans, cardamom, green gram splits, coriander powder, rice bran and cocoa powder were more sorptive (> or =60%), such that the target concentration of 1000 ppm was not achieved at the end of 7 days. For these commodities, increased doses of 3-6 g m(-3) were required to attain 1000 ppm. In-shell almonds, green cardamom, in-shell peanuts, leaf tea, tamarind pulp and sunflower seeds were exceptionally sorptive (>90%), so that 0, 41, 112, 168, 203 and 217 ppm respectively were noted at the end of 7 days; the dose must exceed 6 g m(-3) for effective fumigation of these commodities.

National emission standards for hazardous air pollutants for ethylene oxide commercial sterilization and fumigation operations--EPA. Interim final rule.

Today's action suspends the National Emission Standards for Hazardous Air Pollutants for Ethylene Oxide Commercial Sterilization and Fumigation Operations (EO NESHAP) requirements for chamber exhaust and aeration room vents. The suspension allows affected sources subject to the EO NESHAP to defer compliance with the NESHAP requirements for chamber exhaust and aeration room vents for one year until December 6, 1999. This suspension does not affect the requirement for sources subject to the EO NESHAP to comply with provisions for sterilizer vents by December 6, 1998. This action does not change the level of the standards or the intent of the NESHAP promulgated in 1994.

Fatal accident resulting from methyl bromide poisoning after fumigation of a neighbouring house; leakage through sewage pipes.

An intoxication after using methyl bromide (CH3Br) in fumigation is reported. The accident resulted in the death of a newborn infant within 12-13 h after exposure, as well as clinical intoxication of the infant's parents. The concentration of bromide ion in the infant's blood was 170 mg l-1 and in the parents blood it was 130 and 110 mg l-1. Autopsy showed that the cause of death was acute pneumonia due to aspiration, most likely resulting from vomiting and aspiration after inhalation of CH3Br. The clinical symptoms of the parents are reported, as well as a brief survey on the kinetics and CH3Br toxicity in animals and humans. Reconstruction of the events prior to the intoxication revealed that the sewage pipes serving the two houses had been sucked empty only 1-2 h prior to the start of fumigation, resulting in an open sewage connection between the houses and permitting CH3Br to leak from the treated house into the house of the affected family.

Application of disinfectants in poultry hatcheries.

Veterinary control and routine sanitary procedures in commercial poultry hatcheries should include the following: choice of a suitable geographical location to ensure an isolated site; proper hatchery design with separation of major operations; one-way flow of work within the hatchery; adequate ventilation of each room; routine cleaning and disinfection; formaldehyde fumigation or alternative method for disinfection of eggs, equipment and incubators; a routine programme for monitoring microbial contamination levels within the hatchery.