Conducting environmental health research in the Arabian Middle East: lessons learned and opportunities.

BACKGROUND: The Arabian Gulf nations are undergoing rapid economic development, leading to major shifts in both the traditional lifestyle and the environment. Although the pace of change is brisk, there is a dearth of environmental health research in this region. OBJECTIVE: We describe challenges and successes of conducting an environmental epidemiologic study in the United Arab Emirates (UAE), a Gulf nation in the Middle East, with an inter-disciplinary team that includes in-country academic and government collaborators as well as U.S. academic collaborators. DISCUSSION: We present several issues, including study and data collection design, exposure assessment, scheduling and time coordination, quality assurance and quality control, and institutional review board protocols. These topics are considered in a cultural context. Benefits of this research included building linkages among multinational, interdisciplinary team members, generating data for local environmental decision making, and developing local epidemiologic research capacity. The Middle Eastern culture of hospitality greatly benefited the project team. CONCLUSION: Cultural differences impact multiple aspects of epidemiologic research and should be respectfully addressed. Conducting international population-based environmental research poses many challenges; these challenges can be met successfully with careful planning, cultural knowledge, and flexibility. Lessons learned are applicable to interdisciplinary research all over the world. The research conducted will benefit the environmental and public health agencies of the UAE and provide the nation's leadership with country-specific environmental health data that can be used to protect the public's health in a rapidly changing environment.

Indoor air pollutants and health in the United Arab Emirates.

BACKGROUND: Comprehensive global data on the health effects of indoor air pollutants are lacking. There are few large population-based multi-air pollutant health assessments. Further, little is known about indoor air health risks in the Middle East, especially in countries undergoing rapid economic development. OBJECTIVES: To provide multifactorial indoor air exposure and health data, we conducted a population-based study of indoor air pollution and health in the United Arab Emirates (UAE). METHODS: We conducted a cross-sectional study in a population-based sample of 628 households in the UAE. Indoor air pollutants [sulfur dioxide (SO2), nitrogen dioxide (NO2), hydrogen sulfide (H2S), formaldehyde (HCHO), carbon monoxide (CO), and particulate matter] were measured using passive samplers over a 7-day period. Health information was collected from 1,590 household members via in-person interviews. RESULTS: Participants in households with quantified SO2, NO2, and H2S (i.e., with measured concentrations above the limit of quantification) were twice as likely to report doctor-diagnosed asthma. Participants in homes with quantified SO2 were more likely to report wheezing symptoms {ever wheezing, prevalence odds ratio [POR] 1.79 [95% confidence interval (CI) 1.05, 3.05]; speech-limiting wheeze, POR 3.53 (95% CI: 1.06, 11.74)}. NO2 and H2S were similarly associated with wheezing symptoms. Quantified HCHO was associated with neurologic symptoms (difficulty concentrating POR 1.47; 95% CI: 1.02, 2.13). Burning incense daily was associated with increased headaches (POR 1.87; 95% CI: 1.09, 3.21), difficulty concentrating (POR 3.08; 95% CI: 1.70, 5.58), and forgetfulness (POR 2.68: 95% CI: 1.47, 4.89). CONCLUSIONS: This study provides new information regarding potential health risks from pollutants commonly found in indoor environments in the UAE and other countries. Multipollutant exposure and health assessments in cohort studies are needed to better characterize health effects of indoor air pollutants.

Passive sampler for PM10-2.5 aerosol.

This study investigates the use of a small passive sampler for aerosol particles to determine particulate matter (PM)10-2.5 concentrations in outdoor air. The passive sampler collects particles by gravity, diffusion, and convective diffusion onto a glass coverslip that is then examined with an optical microscope; digital images are processed with free software and the resultant PM10-2.5 concentrations determined. Both the samplers and the analyses are relatively inexpensive. Passive samplers were collocated with Federal Reference Method (FRM) samplers in Chapel Hill, NC; Phoenix, AZ; and Birmingham, AL; for periods from 5 to 15 days. Particles consisted primarily of inorganic dusts at some sites and a mix of industrial and inorganic materials at other sites. Measured concentrations ranged from < 10 microg/m3 to approximately 40 microg/m3. Overall, PM10-2.5 concentrations measured with the passive samplers were within approximately 1 standard deviation of concentrations measured with the FRM samplers. Concentrations determined with passive samplers depend on assumptions about particle density and shape factors and may also depend somewhat on local wind speed and turbulence; accurate values for these parameters may not be known. The degree of agreement between passive and FRM concentrations measured here suggests that passive measurements may not be overly dependent on accurate knowledge of these parameters.

Method to evaluate the dustiness of pharmaceutical powders.

The trend among pharmaceutical companies to develop selective drugs of high potency has pushed the industry to consider the potential of each hazardous ingredient to become airborne. Dustiness issues are not unique to the pharmaceutical industry, but are relevant to any industry where powdered materials are mixed, transferred and handled. Interest in dustiness is also driven by concerns for worker health, the potential for plant explosions and the prevention of product loss. Unlike other industries, the pharmaceutical industry is limited by the milligram quantity of powdered material available for testing during product development. These needs have led to the development of a bench-top dustiness tester that requires only 10 mg of powder and fully contains the generated aerosol. The powder is dispersed within a 5.7 liter glass chamber that contains a respirable mass sampler and a closed-face sampler to quantify the respirable and total dust that are generated with a given energy input. The tester distinguished differences in dustiness levels of five different powders. Finer powders were dustier, and the respirable dust percentage was always less than that for total dust. Four testers have been built and evaluated using pharmaceutical grade lactose. Dustiness measurements determined using all four testers were comparable. The pharmaceutical industry uses surrogates such as lactose to represent active compounds in tests that estimate the dust concentration likely to occur in a new manufacturing operation. Differences between the dustiness of the active compound and its surrogate challenge the relevance of the surrogate tests to represent true exposures in the workplace. The tester can determine the dustiness of both the active compound and its surrogate, and the resultant ratio can help to interpret dust concentrations from surrogate tests. Further, dustiness information may allow the pharmaceutical researcher to select powder formulations that present low airborne concentrations in the workplace.

Sampling and analysis of aircraft engine cold start particles and demonstration of an electrostatic personal particle sampler.

Aircraft engines emit an aerosol plume during startup in extremely cold weather that can drift into areas occupied by flightline ground crews. This study tested a personal sampler used to assess exposure to particles in the plume under challenging field conditions. Area and personal samples were taken at two U.S. Air Force (USAF) flightlines during the winter months. Small tube-and-wire electrostatic precipitators (ESPs) were mounted on a stationary stand positioned behind the engines to sample the exhaust. Other ESPs were worn by ground crews to sample breathing zone concentrations. In addition, an aerodynamic particle sizer 3320 (APS) was used to determine the size distribution of the particles. Samples collected with the ESP were solvent extracted and analyzed with gas chromatography-mass spectrometry. Results indicated that the plume consisted of up to 75 mg/m(3) of unburned jet fuel particles. The APS showed that nearly the entire particle mass was respirable, because the plumes had mass median diameters less than 2 micro m. These tests demonstrated that the ESP could be used at cold USAF flightlines to perform exposure assessments to the cold start particles.

Control methods for mineral oil mists.

Effective mist collection is important, but it is not the only determinant of mist concentration in plant air. Oil-based metalworking fluids such as straight and soluble oils contain semivolatile hydrocarbons. When these fluids form a mist, their semivolatile components partition between the vapor and mist phases depending on the makeup of the mist and on local conditions. This article addresses the relationship between the concentrations of semivolatile hydrocarbons in the vapor and mist phases using theory for partitioning developed in the field of atmospheric chemistry. Mist can be removed effectively in a collector that uses a HEPA filter as its final collection stage. Acceptable HEPA lifetime requires effective upstream stages that reduce mist loading to the HEPA; furthermore, acceptable HEPA performance requires that it be installed and maintained properly. Collectors designed to remove mist do not remove vapor, and as collector exhaust mixes into cooler plant air that already contains some mist, vapor from the collector can repartition to increase the mist concentration in the plant. Assessing the effect of vapor-to-mist repartitioning is complicated; however, repartitioning may be important for many of the compounds contained in oil-based metalworking fluids. Conditions that minimize vapor-to-mist repartitioning, such as ventilating the plant with clean outdoor air, increasing plant temperature, or controlling the release of vapor, may also be expensive, uncomfortable to plant occupants, or impractical from an engineering standpoint. As a result, very low mist concentrations in plant air may be difficult to attain.