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From dust to dust: ethical and practical issues involved in the location, exhumation, and identification of bodies from mass graves.

There are many potential purposes served by the investigation of human remains: criminal fact-finding, archaeological exploration, forensic research, and others. This paper focuses on the identification of remains from mass graves to find missing persons. The primary goal of such efforts is to honor the memory of the dead by bringing closure to living family members, thus supporting the human rights of both the living and the deceased. Cultures, customs, political, and interpersonal specifics will vary, but that singular goal should remain the central guiding principle. This article presents ethical and practical issues resulting from efforts to locate, exhume, and identify the remains of mass fatalities.

Burial↗

Pollutants in house dust as indicators of indoor contamination.

This review summarizes occurrence of organic and inorganic contaminants in house dust and the contribution of house dust as a marker of indoor exposure. Several studies have identified house dust as an important route of toxicant exposure. Often levels of pollutants found in house dust, including compounds banned long ago, are significant sources of exposure for the general population, especially children. House dust is a sink and repository for semivolatile organic compounds and particle-bound matter. Analyses of compounds in house dust are a measure of indoor contamination but may also provide valuable information for assessment of human indoor exposure. The objective of analyzing house dust are to describe the extent, distribution, and determinants of exposure, to identify possible sources of indoor contamination, or to record elevated indoor exposure leading to intervention or sanitation. House dust and compounds adsorbed to house dust may enter the human body by inhalation of suspended and resuspended particles, through nondietary ingestion of dust, through ingestion of particles adhering to food, surfaces in the homes, and on the skin as well as by absorption through the skin. The quantity of dust inhaled and deposited in the differing parts of the alveolar tract is dependent on the aerodynamic diameter. Exposure to house dust does not exclusively and may not even predominantly occur via inhalation, however. For instance, ingestion of house dust particles adhering to food, objects, and the skin or direct absorption through the skin may be primary routes of exposure (Lewis et al. 1994). Samples referred to as "house dust" vary significantly because house dust may be of different origin, amount, and composition and the method of sampling the dust influences the properties of the sample used for analysis. Passive and active sampling methods are described and discussed. For the analysis of organic pollutants in house dust, the < or = 63-microns fraction should be favored because variances caused by inhomogeneity of the subsample are low. Results from studies on house dust are presented for polychlorinated biphenyls (PCB), polycyclic aromatic hydrocarbons (PAH), plasticizers (phthalates, phenols), flame retardants, other organic xenobiotics, and inorganic constituents. If available, medians as a measure of the average concentration and the 90th or 95th percentiles are added as reference values. The review of the literature points out that ingestion of house dust may be a major route of exposure to pesticides for infants and toddlers. So far, only a few guideline values or limiting values for house dust exist. For lead in house dust, the health risk is regulated only in the U.S. and for PAH in the Federal Republic of Germany. Risk associated with the ingestion of contaminated dust by small children (age, 1-6 years; mean body weight, 16 kg) can be estimated using the chronic oral reference dose (RfD) and a daily intake of 100 mg house dust. The tentative benchmark house dust concentrations that are believed to be without health effect for small children were calculated for several compounds from their current RfD. Comparison with the maximum concentrations reviewed for chlorpyrifos, DDT, and diazinon indicates that the tolerable exposure concentration in house dust might be exceeded and that chlorpyrifos especially can be considered as a potential hazard to householders. The role of house dust as an exposure source is gaining more attention over the years but several open questions related to health remain to be resolved. Pesticides applied outside or within the household that are absorbed and preserved by house dust can lead through the everyday activities of children and infants to increased exposure. Residential exposure including house dust residues contribute to combined exposure from dietary and nondietary sources. It is justified to shift more attention to indoor pollution by house dust contamination and to improve the risk assessment of nondietary ingestion, but any health-based standard must be accompanied by a specific dust sampling method.

Air Pollutants↗

Studies on the hazardous effects and the maximum allowable concentration of pyrophyllite dust.

UNLABELLED: Pyrophyllite (H2Al2Si4O22) dust (P-dust) is a mixture of silica (10-40%), different proportions of a luminium oxide (Al2O3), and various metal compounds. People with occupations known to be associated with exposure to P-dust include miners, other industrial workers and persons engaged in artistic carving. Currently, little is known about pyrophyllite pneumoconiosis from P-dust. This study was designed to investigate the hazardous effects of P-dust and to suggest a maximum allowable concentration (MAC) of the dust. This study included four parts: (i) Occupational epidemiology survey in 781 workers from 1 pyrophyllite mine (PM) and four pyrophyllite carving mills (PCM), with a registration rate of 98%. (ii) IN VITRO STUDIES: Six groups of rats were exposed to different levels of P-dust; the cytotoxicity of P-dust on rat alveolar macrophages (AM) was investigated by determining the potassium content of AM and the activity levels of lactate dehydrogenase (LDH) in AM culture fluid, (iii) Mineralogical analysis of P-dust: The contents of silica (SiO2), aluminum (Al), ferrum (Fe), nickel (Ni), zinc (Zn) and copper (Cu) in both PM-dust and PCM-dust were determined. (iv) Determination of P-dust MAC: Using the life-talbe method, an investigation of the hygiene standard of P-dust was carried out in 625 workers exposed to either PM-dust or PCM-dust, upon whom routine radiographs were performed. The results suggest that the risk of developing pneumoconiosis from pyrophyllite dust is significantly higher for PM workers than for PCM workers. The prevalence rate of PCM-dust pneumoconiosis is significantly higher in men than in women. The content of SiO2 and Al2O3 in the mixture of P-dust is the most important factor in the etiology of pyrophyllitosis. Depending on the different P-dust MAC values, we suggest that 2 mg/m3 and 4 mg/m3 should be considered as the MAC for PM-dust and PCM-dust, respectively, and 3 mg/m3 for P-dust. We believe that establishing different hygiene standards is more accurate even though workers are exposed to the "same" dust.

Air Pollutants, Occupational↗

The influence of soil remediation on lead in house dust.

Lead in house dust has long been recognized as a principal source of excess lead absorption among children at the Bunker Hill Superfund Site (BHSS) in northern Idaho. House dust lead concentration from homeowner's vacuum cleaner bags has been monitored since the epidemic of childhood lead poisoning in 1974. Geometric mean house dust lead concentrations decreased from >10000 mg/kg in 1974 to approximately 4000 mg/kg in 1975, in response to air pollution control initiatives at the defective primary lead smelter. After smelter closure, 1983 mean dust lead concentrations were near 3000 mg/kg and were most dependent on soil sources. Following emergency soil removals from public areas and roadsides and fugitive dust control efforts in the mid-1980s, house dust lead decreased by approximately 40-60% to 1200-1500 mg/kg. In 1992, a cleanup goal of 500 mg/kg dust lead community average, with no individual home exceeding 1000 mg/kg, was adopted. This goal was to be achieved by a combination of contaminated soil removals and fugitive dust control efforts throughout the 21 square mile BHSS. Continual reductions in house dust lead concentrations have been noted throughout the residential area soil cleanup. Geometric mean house dust lead concentrations averaged approximately 500-600 mg/kg from 1996 to 1999 and dropped below 500 mg/kg in 2000. Analysis of these data indicates that approximately 20% of the variance in dust lead concentrations is attributed to yard, neighborhood, and community soil lead concentrations. Since 1996, dust lead concentrations and dust and lead loading rates have also been measured by dust mats placed at entryways into the homes. Neighborhood soil lead concentrations, household hygiene, the number of adults living in the home, and the number of hours a child spends outdoors in summer explain approximately 26% of the variance in mat dust lead loading rates. It is estimated that post-remedial house dust lead concentrations will stabilize at 400-500 mg/kg, as compared to approximately 200 mg/kg in socio-economically similar background communities; the difference possibly attributed to residual soil concentrations (3-6 times background), recontamination of rights-of-way, tracking of non-residential mining district soils and dusts, fugitive dusts associated with the remediation, and residual structural or carpet dusts.

Air Pollution, Indoor↗

Dust exposure indices and lung function changes in longshoremen and dock workers.

A group of Dutch harbor workers involved in loading and unloading bulk products from sea vessels such as coal, cokes, and some other products like alumina, borax, phosphate ore, and vermiculite was studied. Exposures were characterized by personal and environmental monitoring. This information was subsequently used to estimate several dust exposure indices and to study relationships with lung function variables and respiratory symptoms. Average respirable dust exposure levels ranged from 0.3-4.0 mg/m3. Workers involved in unloading products from sea vessels were exposed to the highest dust levels. Supervisors and workers with tasks in the dock had an intermediate to low exposure. Office workers had the lowest exposure to respirable dust. Inhalable dust levels were considerably higher and average exposures ranged from 0.3-80 mg/m3. The ranking of occupational titles by inhalable dust exposure was almost identical to the rank order of respirable dust levels. Workers with higher current and cumulative dust exposures tended to have a lower lung function, and only shortness of breath had a statistically significant relationship with current and cumulative inhalable dust exposure. In general, relationships between lung function and inhalable dust levels tended to be somewhat stronger in terms of statistical significance, because inhalable dust is an estimate of dust deposition in the upper airways and lung function is a measurable parameter of airway obstruction in that region. However, the differences with respirable dust were minimal, and variability in dust exposure levels was extremely large for this population. It was concluded that harbor workers involved in unloading ships containing coal and various kinds of ore can be exposed to high dust levels. Relationships between dust exposure and lung function illustrate that these exposures are a respiratory hazard. Our finding that inhalable dust levels have a somewhat stronger relationship with lung function level than respirable dust levels deserves further attention.

Adult↗

Mite antigen in house dust: relationship with different housing characteristics in The Netherlands.

As part of a case-controlled study on the relationship between home dampness and respiratory symptoms of children, the concentration of the major allergen of Dermatophagoides pteronyssinus (Der p I) in floor dust and mattress dust in 516 dwellings in the Netherlands was measured. A checklist, completed by the investigators, was used to obtain information on home and occupant characteristics, which may have an impact on the Der p I concentration in house dust. The geometric mean mite antigen concentrations were 2370 ng Der p I/g floor dust for the living room, 2201 ng Der p I/g floor dust for the bedroom and 5075 ng Der p I/g mattress dust. In 86% of the houses the maximum concentration was higher than 2000 ng Der p I/g dust, that is regarded as representing a risk for genetically predisposed individuals for the development of specific IgE to house dust mite allergen. In 55% of the houses the maximum concentration exceeded 10,000 ng Der p I/g dust, regarded as a risk factor for acute attacks of asthma for mite allergic patients. The Der p I concentrations in dust from carpeted floors were six to 14 times higher than in dust from floors with a smooth floor covering. Higher Der p I concentrations in floor dust were also significantly associated with increasing age of the dwelling and of the floor covering, with an increasing number of occupants, and with the absence of floor insulation. For mattress dust, the age of the mattress, the presence of an outer cavity wall and mechanical ventilation were important factors. Older mattresses had higher levels, and mattress dust from bedrooms with solid brick outer walls had higher levels than that from bedrooms with outer cavity walls. Mattresses in homes with continuous mechanical ventilation had almost twice lower levels than mattresses in homes with natural ventilation. There was a tendency towards higher Der p I concentrations in dust in homes with reported or observed signs of dampness. The Der p I concentrations in dust from carpeted bedroom floors and mattresses were positively associated with the average relative humidity in the bedroom over a period of 3-6 weeks in a subset of the homes where relative humidity was measured. Similar results were obtained using the concentrations of Der p I in ng/m2 instead of ng/g dust. The results obtained in this study are of importance for planning and evaluating allergen avoidance measures advised to mite allergic patients.

Adult↗