Frank. S. Rosenthal

Despite the proximity and interconnections between Israel and the Occupied Palestinian Territories (oPt), great disparities persist in health status between these two regions. This disparity is seen in infant, child and maternal mortality, life expectancy, mortality rates for leading causes of death and measures of mental well-being. This paper compares health indicators between oPt and Israel and examines the social determinants of health that may be responsible for differences between them. Data on health indicators were obtained from publicly available publications or websites of the World Health Organization and The World Bank, as well as the database of the Global Burden of Disease Project of the Institute of Health Metrics and Evaluation. Data on the social determinants of health were obtained from publications and websites of the United Nations, the World Bank, the U.S. Central Intelligence Agency, Palestinian and Israeli government reports, reports from non-governmental organisations, peer-reviewed studies and news articles. The health disparities are due to a complex mix of factors involving economic conditions, food insecurity, environmental exposures, psychological trauma and stress, and access to health services, most of which can be related directly or indirectly to the Israeli military occupation of oPt.

Out-of-hospital cardiac arrest (OHCA) has been previously associated with exposure to particulate air pollution. However, there is uncertainty about the agents and mechanisms that are involved. We aimed to determine the association of gases and particulates with OHCA, and differences in pollutant effects on OHCAs due to acute myocardial infarction (AMI) vs those due to other causes. Helsinki Emergency Medical Services provided data on OHCAs of cardiac origin (OHCA_Cardiac). Hospital and autopsy reports determined whether OHCAs were due to AMI (OHCA_MI) or other cardiac causes (OHCA_Other). Pollutant data was obtained from central ambient monitors. A case-crossover analysis determined odds ratios (ORs) for hourly lagged exposures (Lag 0–3) and daily lagged exposures (Lag 0d–3d), expressed per interquartile range of pollutant level. For OHCA_Cardiac, elevated ORs were found for PM2.5 (Lag 0, 1.07; 95% confidence interval (CI): 1.01–1.13) and ozone (O₃) (Lag 2d, 1.18; CI: 1.03–1.35). For OHCA_MI, elevated ORs were found for PM2.5 (Lag 0, 1.14; CI: 1.03–1.27; Lag 0d, 1.17; CI: 1.03–1.33), accumulation mode particulate (Acc) (Lag 0d, 1.19; CI: 1.04–1.35), NO (Lag 0d, 1.07; CI: 1.01–1.13), and ultrafine particulate (Lag 0d, 1.27; CI: 1.05–1.54). For OHCA_Other, elevated ORs were found only for O₃ (Lag 1d, 1.26; CI: 1.07–1.48; Lag 2d, 1.30; CI: 1.11–1.53). Results from two-pollutant models, with one of the pollutants either PM2.5 or O₃, suggested that associations were primarily due to effects of PM2.5 and O₃, rather than other pollutants. The results suggest that air pollution triggers OHCA via two distinct modes: one associated with particulates leading to AMI and one associated with O₃ involving etiologies other than AMI, for example, arrhythmias or respiratory insufficiency.

Background: Previous studies have found particulate matter (PM) < 2.5 μm in aerodynamic diameter (PM2.5) associated with heart disease mortality. Although rapid effects of PM2.5 exposure on the cardiovascular system have been proposed, few studies have investigated the effect of short-term exposures on out-of-hospital cardiac arrest (OHCA). Objectives: We aimed to determine whether short-term PM2.5 exposures increased the risk of OHCA and whether risk depended on subject characteristics or presenting heart rhythm. Methods: A case–crossover analysis determined hazard ratios (HRs) for OHCAs logged by emergency medical systems (EMS) versus hourly and daily PM2.5 exposures at the time of the OHCA and for daily and hourly periods before it. Results: For all OHCAs (n = 1,374), exposures on the day of the arrest or 1–3 days before arrest had no significant effect on the incidence of OHCA. For cardiac arrests witnessed by bystanders (n = 511), OHCA risk significantly increased with PM2.5 exposure during the hour of the arrest (HR for a 10-μg/m3 increase in PM2.5 exposure = 1.12; 95% confidence interval, 1.01–1.25). For the subsets of subjects who were white, 60–75 years of age, or presented with asystole, OHCA risk significantly increased with PM2.5 during the hour of the arrest (HRs for a 10-μg/m3 increase in PM2.5 = 1.18, 1.25, or 1.22, respectively; p < 0.05). HR generally decreased as the time lag between PM2.5 exposure and OHCA increased. Conclusion: The results suggest an acute effect of short-term PM2.5 exposure in precipitating OHCAs, and a need to investigate further the role of subject factors in the effects of PM on the risk of OHCA.

This study used aerosol probes and lung function tests to investigate whether all trans retinoic acid (RA) can reverse experimental emphysema in dogs. Three dogs were evaluated with lung mechanics tests, including inspiratory capacity (IC), total lung capacity (TLC), and the ratio of forced expired volume in 0.5 sec to forced vital capacity (FEV0.5/FVC), an aerosol-derived measure of pulmonary airspace size (effective airspace diameter, EAD), and an aerosol-derived measure of nonuniform ventilation (aerosol dispersion, AD). Emphysema was induced by exposure to aerosolized papain. At 11 or 12 weeks postpapain exposure, dogs received oral RA (2 mg/kg/day) for 8 weeks, and were followed for an additional 4 weeks after stopping RA treatment. In all dogs, lung injury increased in the first 11–12 weeks following papain exposure, as evidenced by increasing trends of inspiratory capacity IC, TLC, EAD, and AD, and a decreasing trend of FEV0.5/FVC. These parameters of lung injury partially and transiently reversed their trends between 2 and 6 weeks following the initiation of RA treatment. A sham RA-treated group was not studied. However, similar reversals of lung injury were not seen in a previous study of dogs treated with papain but not RA, suggesting that RA altered emphysema progression in the current study. The limited reversal of lung injury in this study contrasts with more pronounced treatment effects seen in previous studies with rats. This paper discusses possible reasons for differences in these studies, as well as suggestions for improved experimental investigations of emphysema therapies.

Measurements of total, respirable, and real-time airborne particulate were obtained in 12 horse barns in summer and winter. Respirable and total particulate concentrations were measured gravimetrically; real-time particulate was measured with an aerosol photometer. Total particulate (TP) ranged from nondetectable (ND) to 2.1 mg/m³ and from ND to 1.2 mg/m³ for winter and summer sampling, respectively. Respirable particulate (RP) ranged from ND to 0.2 mg/m³ and from ND to 0.7 mg/m³ for winter and summer measurements, respectively. The mean respirable fraction of particulate for summer and winter measurements was 0.63 and 0.34, respectively Real-time particulate (RTP) concentration was significantly correlated with TP for winter measurements and for pooled data but was not significantly correlated with RP for winter, summer, or pooled measurements. Peak, 10-sec average levels of RTP were estimated to range up to 22 mg/m³ in the samples collected. The data suggest that (a) airborne particulate concentrations and particle size distributions vary considerably among horse barns, and (b) real-time sampling, with an aerosol photometer, may be a more reliable measure of airborne TP than airborne RP in these environments.

An image-based method was developed in order to determine chord lengths in sections of dog and sheep lungs air-dried at 25 cm H2O transpulmonary pressure. To facilitate image processing, optical contrast in the sections was optimized with respect to section thickness, stain type, stain concentration, staining temperature, staining time and clearing method. Digital processing of images used standard procedures, e.g. thresholding, dilation and thinning, as well as algorithms written to subtract background, delete spots and measure chord lengths. Correlation of image-based vs. manual determination of mean chord length in 17 sections from a sheep lung, stained for optimal contrast yielded an R2 of 0.82 (P < 0.0001). For 95 sections from three dog lungs, stained with lower contrast, R2 was 0.65 (P < 0.0001). Weaker correlations were observed between image-based and manual determinations of the standard deviation, the geometric standard deviation, and the 95th percentile of chord lengths (P < 0.05). The results show that image-based stereology of inflated air-dried lungs can provide valid measures of mean chord length and other statistics of chord length distribution.

The transmission of ultraviolet radiation (UVR) from an ultraviolet transilluminator through three types of laboratory gloves (latex, nitrile, vinyl) was determined using two independent methods. First, transmittance was measured with a radiometer equipped with UVA and actinic UV detectors. Second, a spectrophotometer was used to determine the UVR transmittance vs. wavelength (250–440 nm); this data was then used to compute the effective attenuation of the glove material. The average UVA percent transmittance using the radiometer method with an unstretched glove was 73.4%, 0.18%, and 1.10% for vinyl, nitrile, and latex, respectively. The average actinic percent transmittance for an unstretched glove was 13.3%, 0.015%, and 0.024% for vinyl, nitrile, and latex, respectively. Slight increases in UVR transmittance resulted from stretching the gloves by 30% or wetting them with saline. Six hours of UVR exposure decreased transmittance of vinyl gloves and increased transmittance by latex gloves. Results from the spectrophotometer method and radiometer methods of determining UVR transmittance agreed that vinyl gloves had the highest transmittance; however, the spectrophotometer method greatly overestimated UV glove attenuation due to the effect of light scattering by the glove material. The study suggests that in some circumstances, vinyl gloves will provide inadequate protection against workplace ultraviolet radiation.

The concentrations and size distribution of metalworking fluid aerosols were investigated in grinding operations in the bearing manufacturing industry. Fifteen paired open- and closed-face cassette samples and five cascade impactor samples were obtained in each of three types of grinding machinery (face, microcentric, and progressive). Aerosol mass concentration as measured by open-face filter sampling ranged from 0.34 to 2.43 mg/m³. As measured by closed-face sampling the range was 0.14 to 2.01 mg/m³. For each grinding process, open-face concentration was significantly higher than the closed-face concentration (paired t-test, p <0.05). Mass median aerodynamic diameter (MMAD) ranged from 3.33 to 6.26 µm. The percentage of mass greater than 9 µm ranged from 8.0 to 45.3. The MMAD and fraction greater than 9 µm were significantly greater for the aerosol produced by the face grinder compared with the other two processes. The results indicate that (1) closed-face sampling results in a lower aerosol mass concentration, as compared with open-face sampling, with the degree of difference being somewhat dependent on grinding process; and (2) the particle size distribution and concentration of metalworking fluid aerosols may vary with the type of grinding operation sampled.

When the deposition of aerosol boluses is used to estimate mean pulmonary airspace size, an implicit assumption is made that the inhaled particles are distributed uniformly among normal and diseased lung regions. This assumption was examined in a series of dogs in which emphysema was experimentally induced by exposure to papain. After the experimental disease had developed for several weeks, boluses of fluorescent particles were inhaled, using a breathing pattern similar to that used for aerosol measurements of airspace size. The lungs were then excised and 18–20 tissue blocks were obtained from each lung. A section from each tissue block was analyzed to determine the mean liner intercept (Lm), which was considered as an index of lung injury. In the same sections, the density of particles was determined by counting particles in a number of microscopic fields and dividing the particle count by the number of fields sampled. Correlation analysis generally revealed a negative correlation of particle density with Lm, indicating fewer particles being delivered to diseased regions. One lung, however, showed a positive correlation between particle density and Lm. Correction for the fractional deposition of aerosol in the lung regions weakened but did not reverse the relationship between particle density and Lm. A model calculation of the effect of the observed nonuniform distribution of aerosol on the determination of airspace size found a negligible effect of uneven ventilation on mean airspace size determination in this experimental preparation.