Feasibility of the hydrogen sulfide test for the assessment of drinking water quality in post-earthquake Haiti

In 2010, a magnitude 7.0 earthquake struck Haiti, severely damaging the drinking and wastewater infrastructure and leaving millions homeless. Compounding this problem, the introduction of Vibrio cholerae resulted in a massive cholera outbreak that infected over 700,000 people and threatened the safety of Haiti’s drinking water. To mitigate this public health crisis, non-government organizations installed thousands of wells to provide communities with safe drinking water. However, despite increased access, Haiti currently lacks the monitoring capacity to assure the microbial safety of any of its water resources. For these reasons, this study was designed to assess the feasibility of using a simple, low-cost method to detect indicators of fecal contamination of drinking water that could be implemented at the community level. Water samples from 358 sources of drinking water in the Léogâne flood basin were screened with a commercially available hydrogen sulfide test and a standard membrane method for the enumeration of thermotolerant coliforms. When compared with the gold standard method, the hydrogen sulfide test had a sensitivity of 65 % and a specificity of 93 %. While the sensitivity of the assay increased at higher fecal coliform concentrations, it never exceeded 88 %, even with fecal coliform concentrations greater than 100 colony-forming units per 100 ml. While its simplicity makes the hydrogen sulfide test attractive for assessing water quality in low-resource settings, the low sensitivity raises concerns about its use as the sole indicator of the presence or absence of fecal coliforms in individual or community water sources.     

Studies on the drug resistance profile of Enterococcus faecium distributed from poultry retailers to hospitals

The multidrug resistant Enterococcus faecium (MEF) strains originating from farm animals are proliferating at a substantial pace to impact downstream food chains and could reach hospitals. This study was conducted to elucidate the drug susceptibility profile of MEF strains collected from poultry products in Ann Arbor, MI area and clinical settings from Michigan State Lab and Moffitt Cancer Center (MCC) in Florida. Presumptive positive Enterococcus isolates at species level were identified by Matrix Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) analysis. The antibiotic susceptibility profile for both poultry and clinical strains was determined by the Thermo Scientific's Sensititre conform to the National Committee for Clinical Laboratory Standards (NCCLS) and validated via quantitative real-time PCR (qPCR) methods. Out of 50 poultry samples (Turkey: n = 30; Chicken: n = 20), 36 samples were positive for Enterococcus species from which 20.83% were identified as E. faecium. All the E. faecium isolates were multidrug resistant and displayed resistance to the last alternative drug, quinupristin/dalfopristin (QD) used to treat vancomycin resistant E. faecium (VRE) in hospitals. Results indicate the presence of MEF strains in food animals and clinical settings that are also resistant to QD.     

Measuring the Improvements in the Control Aspects of Programs Aided by Federal Grants

Ambient air standards, emission standards, and program activities are considered in a search for appropriate indices for measuring program progress and effectiveness. The authors suggest that such indices can best be based on data related to weight of emissions. Several methods for expression accomplishment are presented for consideration.     

The Use of Aircraft in Air Pollution Research

An instrumented single engine aircraft is being used to characterize plumes from large emission sources. By cross sectioning these plumes at a number of points we hope to describe the character and concentration of pollution as it ages and travels downwind under known meteorological conditions. This paper reports experimental work thus far completed on aerosol measurement. Flights have been made through plumes from a large coal-fired power station, forest fires, and a gravel plant. Particle counts in various size classifications were made with a Bausch and Lomb 40–1 Dust Counter which was carried in the aircraft. Selected meteorological parameters were recorded. Results show the aerosol concentrations in various size classifications that are found at successive distances downwind from these sources for distances up to 32 miles. Background aerosol concentrations are also reported, and variations in these can be noted with respect to time, location and altitude.     

controlled open burning in the san francisco bay area

Intermingled land usage in the 3900 square mile Bay Area Air Pollution Control District presented special problems in curtailing open burning. Regulation 1, adopted in 1957, prohibited most types of open burning, with exceptions for public safety, instruction in fire fighting, flood control, agricultural burning and one- and two-family dwellings.Variances for open burning could be granted by the District’s Hearing Board.The need was established for utilizing the services of professional meteorologists for planning and carrying out open burns.Their proposals to limit adverse effects were : (1) Select a day of no inversion, with wind direction to carry pollutants away from local targets; and, (2) a day of low velocity at ground level, high velocity at high altitudes. Predicted meteorological conditions have been met for up to eight hours in a high percentage of cases. Experience has proven the need for proper stacking and drying of the wood waste to assure high temperature burning, and completion of the burn as scheduled. Even though the cost of hauling to landfills may be substantially more than the cost of burning under a variance, hauling is often selected because of the time required for stacking, drying, and waiting for designated meteorological conditions. Substantial progress has been made in curtailing agricultural burning. Burning of greenhouse waste has been stopped.on emissions from orchard heaters has resulted in replacement with new smokeless heaters.Orchard brush can be burned only on “burn days” designated in the winter when the inversion is predicted to be above 2500 ft. Stubble burning has continued due to the lack of a feasible alternative. Range brush burning also continues, mostly in remote areas of high elevation. Lumbering slash is burned at the insistence of forestry officials. The above burning could be limited to designated burn days, as is successfully being applied to orchard brush. Research on alternatives to agricultural burning is being spearheaded by the University of California, and its agricultural extension service. Each project usually requires several years to carry out and evaluate. Closer cooperation by all involved in agriculture and air pollution control is necessary to develop feasible alternatives to open burning.     

Citizen Complaints of Air Pollution In Northeastern Illinois

In 1964, as part of the Northeastern Illinois Metropolitan Planning Commission's Air Resource Management Study, an examination was made of citizen complaints of air pollution registered with air pollution control agencies representing the City of Chicago, outlying Cook County, and the State of Illinois. The complaint files of the City of Chicago were found to contain the addresses of some 9500 air pollution sources specified by complainants in complaints covering the time period from approximately 1954 to 1964. A statistical sample of these sources showed more than 70% to be of a nonindustrial nature, with domestic fuel burning or incineration by neighbors most often specified. There were 1119 industrial process source snamed in the Chicago files; 588 nonmanufacturing and 531 manufacturing. Fabricated metal industries, primary metal industries, chemical manufacturers, and food processing plants were cited more often than other industrial categories. Complaint sources named in complaints filed by citizens with the State of Illinois, and with Cook County, differed with those of Chicago in that industrial sources were specified more often than nonindustrial ones. The reason for this is believed to lie in the reduced residential densities and the relatively great use of pollution-free fuels in the metropolitan area outside of the City of Chicago.     

Measurement of Exhaust Emissions in Piston And Diesel Engines by Dispersive Spectroscopy

A versatile but simple, reliable, rugged, and compact vehicle exhaust monitoring system has been developed, allowing detection of carbon monoxide (CO), carbon dioxide (COo), high and low hydrocarbons (HHC and LHC), and nitric oxide (NO). The analysis is performed by dispersive absorption spectroscopy with instrumentation designed and fabricated for this demanding industrial environment. The operation of the instrumentation is described here, as well as results for both diesel and piston engine emission testing. This equipment has been used for California 7 mode-7 cycle hot start and cold start tests, the California heavy-duty engine test cycles, EPA CVS tests reading bag samples and also continuous dilute, and finally it has been used for idle checks. Testing has been performed on production automobiles, as well as those equipped with thermal reactors or catalytic mufflers, and also both heavy-duty gasoline and diesel. engines. The instrumentation has shown very good correlation with other established techniques, and because of its sensitivity, selectivity, ruggedness, and simplicity, has been shown to be suitable for vehicle emission analysis. Applications include assembly-line testing, engine testing, certification testing, quality audit testing, emission lab testing, and research.     

The Impact of Stratospheric Ozone on Tropospheric Air Quality

A background of ozone (O₃), principally of stratospheric origin, is present in the lower free troposphere. Typical mean O₃ levels of 50 ppb, 40 ppb, and 30 ppb are encountered here in spring, summer, and fall, respectively. Maximum hourly O₃ concentrations which are twice these mean values can be expected. Ozone from the free troposphere is routinely brought down to ground level under turbulent atmospheric conditions. Deep and rapid Intrusions of stratospheric air into the lower troposphere are associated with low-pressure troughs and occur regularly. In the mid troposphere, O₃ levels as high as 300 ppb are found within these intrusions. Observational data showing these intrusions, containing high O₃ concentrations, to directly reach ground level are currently lacking. Over the United States, an intrusion was present aloft on 8 9% of the days in 1978. The frequency, however, is somewhat reduced in summer and a northward movement is evident. During 1978, no intrusion occurred south of 30°N between June and August and none south of 40 °N in August.

The hypothesis that low levels of stratospheric O₃ produce disproportionately large amounts of O₃ in the polluted atmosphere cannot be supported from currently known chemistry but should be studied further. The experimental technique involving a ⁷Be/O₃ ratio to estimate the daily stratospheric component of ground level O₃ is unverified and considered to be inadequate for air quality applications. Estimates resulting from such a technique are considered uncertain by a factor of more than three. Specially designed aircraft studies provide the best means to determine quantitatively the impact of stratospheric O₃ on ground level air quality.