Environment, pregnancy complications, and omics
Moshe Hod, Vincenzo Berghella, Mary E. D'Alton, Gian Carlo Di Renzo, Eduard Gratacós, Vassilios Fanos in New Technologies and Perinatal Medicine, 2019
The human environment encompasses diverse domains including the air that we breathe, natural water resources, nutrition, and soil. These are influenced by our financial, geographical, social, and educational status, as well as other factors. Elevated concentrations of greenhouse gases have increased ambient temperatures worldwide (1); this has been associated with increased morbidity and mortality rates (2). An average human being consumes around 20,000 breaths per day, exposing us each day to one of our generation's greatest disease burdens, air pollution. The World Health Organization (WHO) defines air pollution as the presence of one or more substances in the air reaching a high enough concentration to induce deleterious effects to living organisms, including humans (3). The Global Burden of Disease (GBD) 2015 study estimated that air pollution accounts for about 9,000,000 premature deaths annually (4). Air pollution levels vary according to region and are particularly high in Africa, Asia, and the Middle East (3). In addition, the GBD 2015 study concluded that 90% of deaths attributed to environmental exposure arise in mid-income countries (4).
Inhalation Toxicity of Metal Particles and Vapors
Jacob Loke in Pathophysiology and Treatment of Inhalation Injuries, 2020
Urban air contains potentially toxic salts of metals such as cadmium, lead, antimony, selenium, thallium, vanadium, nickel, and zinc. Often these compounds are “enriched” in polluted urban air up to 1000-fold above the average levels at which these metals occur in the earth’s crust (Natusch et al., 1975). Most toxic components of air pollution emanate from automobile exhausts, coal-fired power plants, incinerators, metallurgical and refinery operations, and aerosol cans of cosmetics, pesticides, paints, varnishes, and propellants. Humans and animals are exposed to these pollutants more through inhalation than through other modes of intake. Most metal compounds, while exerting some transient or secondary toxic effects in the lung, also produce toxic effects at primary sites elsewhere in the body.
Quantitative Cancer Risk Assessment
Peter G. Shields in Cancer Risk Assessment, 2005
For the general public, air levels have also been developed by air toxics programs of the states. In the case of the general public, risks of one per one-hundred thousand (10–5) or one per million (10–6) are generally used as a starting point. The 10–6 risk level has been chosen historically in an arbitrary manner as a basis for regulation (17), and the EPA has regulated chemicals involving exposures to large populations at about this risk level. For decisions where the population risk is a fraction of a cancer case per year for the entire population, a 10–5 risk level seems to be in the range of what EPA might consider to be an insignificant average individual lifetime risk (18). A review of policies by Travis et al. (19) has found that EPA does not consider individual risks of less than 10–4 in small geographic areas to necessarily require regulation. The legislation that created superfund clean-up standards has indicated that a range of 10–4–10–6 risk level is generally acceptable. At these specified hypothetical risk levels, the actual risk to an individual is usually negligible due to the many health protective assumptions that are incorporated into the risk assessment process.
Enclosure design for flock-level, chronic exposure of birds to air contaminant mixtures
Published in Toxicology Mechanisms and Methods, 2018
Michelle A. North, David W. Kinniburgh, Judit E. G. Smits
There are two principal methods for studying the effects of exposure to air contaminants in animals: laboratory-based inhalation toxicology and ecotoxicology field studies. Laboratory studies typically involve the high-concentration, short duration exposure of traditional research species (such as rats, mice and guinea pigs) to single compounds or limited mixtures (Hinners et al. 1966), and require significant experience in engineering and chemistry. Field studies investigate the effects of exposure to common environmental mixtures of contaminants using diverse species including small- (Borras et al. 1998) or large (Waldner et al. 2001) mammals, birds (Cruz-Martinez et al. 2015a), or multi-species comparative studies (Llacuna et al. 1993), and require extensive biological expertise, including knowledge of physiology and population-ecology. Epidemiological research into the effect of air pollution on human health are a third method of studying the toxicology of air pollutants, and will not be discussed here. While experimental, laboratory-based studies and field studies each have distinct advantages, the disadvantages can complicate our understanding of the consequences of exposure to realistic pollutant mixtures in wildlife species. This study controls many of those disadvantages, while retaining the advantage of ensuring environmentally relevant results (Table 1).
The shape of low-concentration dose–response functions for benzene: implications for human health risk assessment
Published in Critical Reviews in Toxicology, 2021
Louis A. Cox, Hans B. Ketelslegers, R. Jeffrey Lewis
Supralinear dose–response functions – that is, dose–response functions in which low doses are disproportionately potent in causing harm – have sometimes been proposed as describing the risks from many well-studied public and occupational hazards. Examples include asbestos, benzene, lead, particulate air pollution, and ionizing radiation. A suggested risk management implication is that exposure concentrations must be driven to zero, or close to it, to adequately protect human health (Hornung and Lanphear 2014; Lanphear 2017). Some of these concerns have been challenged as statistically flawed or as biologically unrealistic (Waddell 2006; Hornung and Lanphear 2014). For example, studies that identify supralinear dose–response relationships can be questioned if they fail to control fully for important potential confounders, such as misclassified smoking (Hamling et al. 2019). Omitted and residual confounding by smoking can create significant associations between some common exposure metrics (e.g. blood lead levels) and adverse health effects (e.g. cardiovascular mortality and morbidity) whether or not the former affect the latter. Misattributing risk caused by a confounder to exposure creates the appearance of a supra-linear dose–response function since risk fails to decline as exposure decreases, in effect spreading the same risk over fewer units of exposure.
Saving Environmental Justice From Proceduralism
Published in The American Journal of Bioethics, 2018
With that clarification, consider the following argument. Assume that the Revision and Appeals Condition and the Regulative Condition are met—that is, roughly, that an institution provides a means for appeal and revision of decision about a policy and regulation of that policy. Consider some policy P in environmental health policy that a government might institute. In virtue of the Publicity and Relevance Conditions, AFR is committed to holding that policy P in that domain is just if and only if Institution I produces P via actual democratic deliberation that employs only public reasons, which I must publicize. Yet, consider a variation on Resnik and colleagues' “Air pollution standards.” Air pollution standards*. A regulatory agency is attempting to determine whether to enhance air pollution protections. Lowering the current ozone standard by 25% will provide modest protections for the general population and substantial protections for people with respiratory diseases. A 25% reduction in the ozone standard will decrease in the next 2 years. However, these losses will be recuperated over the next 5 years as the added production from work days that are not missed due to personal or family illness will make up for the monetary costs of ensuring compliance with the new standard.
Related Knowledge Centers
- Acid Rain
- Ammonia
- Biomolecule
- Carbon Monoxide
- Chlorofluorocarbon
- Methane
- Ozone Depletion
- Sulfur Dioxide
- Biological Agent
- Particulates