Air quality, tobacco smoke, urban crowding and day care: modern menaces and their effects on health

Relative deprivation, inequality and the Covid-19 pandemic

There is a growing concern that inequalities are hindering health outcomes. This paper's primary objective is to investigate the role of relative deprivation and inequality in explaining the daily spread of the Covid-19 pandemic. For this purpose, we use secondary cross-sectional data across 119 (developed and developing) countries from January 2020 – to April 2021. For the empirical analysis, we use a recent dynamic panel data modelling approach that allows us to identify the role of time-invariant variables such as degree of globalisation, political freedom and income inequality on the dynamics of the pandemic and fatality rates across countries. We find that new cases per million and fatality rates are highly persistent processes. After controlling for time-varying mobility statistics from the Google mobility database and region-specific dummy variables, the two significant factors that explain the severity of Covid-19 spread in a country are per-capita Gross Domestic Product (GDP) and Yitzhaki's relative income deprivation index. Lagged value of new cases per million significantly explains cross-country variations in the daily case fatality rates. A higher proportion of the older population and pollution increased fatality rates while better medical infrastructure reduced it.

Environmental risk factors for acute respiratory infections in hospitalized children under 5 years of age in Ibadan, Nigeria

BACKGROUND

Acute respiratory infections (ARIs) are the fourth major cause of morbidity and mortality among children under 5 worldwide. However, information on the risk factors that could predispose children under 5 to ARIs is scanty in Nigeria.

AIM

To assess which environmental factors contribute to the acquisition of ARIs in children under 5 in Ibadan.

METHODS

A case-control study was undertaken. 220 children under 5 with ARI (cases) and 220 without ARI (controls) were selected consecutively from children visiting Oni Memorial Children's Hospital and University College Hospital, Ibadan. A pre-tested six-section questionnaire was administered to mothers to elicit information on factors that contribute to the acquisition of ARIs in children under 5.

RESULTS

Mean (SD) ages of cases and controls were 20·4 (14·7) and 20·3 (15·0) months, respectively. Mean (SD) household size of cases was 6·0 (1·5) compared with 4·0 (1·7) for the controls (P = 0·01). Children whose homes had more than two persons per room were found to have a 14-fold greater risk of ARI than children in houses with fewer than two persons per room. The use of a lantern at night (OR 4·1, 95% CI 2·4-6·9) and firewood for cooking (OR 9·3, 95% CI 3·6-24·1) were found to be independent risk factors for ARIs.

CONCLUSION

Cases were more exposed than controls to environmental risk factors for ARIs. Increased awareness of the importance of environmental factors with regard to prevention and control of ARI is therefore important.

A unifying hypothesis of schizophrenia: abnormal immune system development may help explain roles of prenatal hazards, post-pubertal onset, stress, genes, climate, infections, and brain dysfunction

We propose a unifying hypothesis of schizophrenia to help reconcile findings from many different disciplines. This hypothesis proposes that schizophrenia often involves pre- or perinatal exposure to adverse factors that produce a latent immune vulnerability. When this vulnerability is manifested, beginning around puberty with changes in immune function and involution of the thymus, individuals become more susceptible to infections and immune dysfunctions that contribute to schizophrenia. Our hypothesis suggests theoretical bridges between different lines of evidence on schizophrenia and offers explanations for many puzzling findings about schizophrenia. For example, the hypothesis helps account for why schizophrenia patients tend to have had increased exposure to neurotropic infections, but most individuals with such exposure do not develop schizophrenia, and why prenatal hardships increase risk for schizophrenia, but the onset of symptoms typically does not occur until after puberty. The hypothesis also explains another paradox: lower socioeconomic status and poor prenatal care increase risk for schizophrenia at the same geographic site, but international comparisons indicate that countries with higher per capita incomes and better prenatal care actually tend to have higher schizophrenia prevalences. As the hypothesis predicts, (1) prenatal adversity, which increases risk for schizophrenia, also impairs post-pubertal immune competence, (2) schizophrenia patients experience elevated morbidity from infectious and auto-immune diseases, (3) genetic and environmental risk factors for schizophrenia increase vulnerability to these diseases, (4) factors that exacerbate schizophrenic symptoms also tend to impair immune function, (5) many anti-psychotic medications combat infection, (6) effects of early infections may not appear until after puberty, when they can produce neurologic and psychiatric symptoms, and (7) immune dysfunctions, such as imbalances of pro- and anti-inflammatory cytokines, may contribute to the onset of psychotic symptoms and the progressive loss of brain tissue in schizophrenia. The disruptive effects of prenatal adversity on the development of the immune system may often combine with adverse effects on prenatal brain development to produce schizophrenia. This paper focuses on the adverse immune system effects, because effects on the brain have been extensively discussed in neurodevelopmental theories of schizophrenia. We propose new tests of scientific predictions. We also point out potential clinical implications of the hypothesis; for example, individuals with schizophrenia may often have underlying infections or immune dysfunctions, such as imbalances in inflammatory cytokines, that contribute to the illness. This possibility could be tested experimentally--e.g., by clinical trials in which patients' exposure to infection is reduced or immune function is normalized.

Environmental and occupational allergies

Airborne allergens are the major cause of allergic rhinitis and asthma. Daily exposure comes from indoor sources, chiefly at home but occasionally at schools or offices. Seasonal exposure to outdoor allergens, pollens, and molds is another important source. Exposure to unusual substances at work causes occupational asthma, accounting for about 5% of asthma in adults. Indoor and outdoor air pollutants trigger airway inflammation and increase the severity of asthma. Diesel exhaust particles increase the production of IgE antibodies. Identification and reduction of exposure to allergens is a very important part of the management of respiratory allergic diseases. The first section of this chapter discusses domestic allergens, arthropods (mites and cockroaches), molds, and mammals (pets and mice). Indoor humidity and water damage are important factors in the production of mite and mold allergens, and discarded human food items are important sources of proliferation of cockroaches and mice. Means of identifying and reducing exposure are presented. The second section discusses outdoor allergens: pollens and molds. The particular plants or molds and the amount of exposure to these allergens is determined by the local climate, and local pollen and mold counts are available to determine the time and amount of exposure. Climate change is already having an important effect on the distribution and amount of outdoor allergens. The third section discusses indoor and outdoor air pollution and methods that individuals can take to reduce indoor pollution in addition to eliminating cigarette smoking. The fourth section discusses the diagnosis and management of occupational asthma.

Impact of environmental tobacco smoke and active tobacco smoking on the development and outcomes of asthma and rhinitis

PURPOSE OF REVIEW

We aim to discuss current insights on the influence of active smoking and environmental tobacco smoke in lower and upper respiratory inflammatory illnesses.

RECENT FINDINGS

Insight has been gained on the effect of tobacco smoking on the development of asthma from the womb to adolescence. Secondhand tobacco exposure and active smoking play a major role not only in the inception of asthma epidemiological community studies but also in patients already suffering from allergic rhinitis. Tobacco seems to influence innate immunity predisposing to Th2-associated respiratory diseases and increasing the risk for IgE-mediated sensitization. Tobacco smoking is related to worst outcomes in both asthma and rhinitis.

SUMMARY

Several deleterious effects have been described in asthma because of smoking: accelerated decline in lung function, more severe symptoms, impairment in quality of life and diminished therapeutic response to steroids. The harmful effect of tobacco smoking is not only on asthma but also on rhinitis playing a role in disease outcomes. Tobacco exposure can influence innate immunity diminishing innate production of antigen-presenting cells cytokines, as well as an impaired response to toll-like receptor ligands. Active smoking is associated with current symptoms of asthma and rhinitis and seems to be a risk factor for developing new asthma in patients with rhinitis. Tobacco smoking has been also found among the factors inducing nasal obstruction and decreased muco-ciliary clearance in nonallergic rhinitis.

Maternal employment in child-care institutions and the risk of infant wheeze and atopic dermatitis in the offspring

It has been proposed that exposure to infections and microbes protects against atopic diseases, but epidemiological data has so far been conflicting. We hypothesized that maternal exposure to infections and microbes before or during pregnancy would be of particular importance. To test this hypothesis, we studied the incidence of wheezing and atopic dermatitis (AD) in infants of mothers employed in child-care institutions - and thus presumably being highly exposed to infections and microbes - compared with infants of mothers not so employed. A total of 31471 mother-child pairs enrolled in the Danish National Birth Cohort were followed prospectively. Information on wheezing episodes, AD, maternal employment, and other variables were collected by interview at 12 and 30 wk of gestation, and 6 and 18 months of age, and by linkage to the Danish Medical Birth Register and the Child-care Database. The relative risk was estimated in Cox proportional hazard models. Analyses were stratified by sibling status (first born or not), as older siblings are likely to be a significant source of infectious agents. The adjusted relative risks of wheeze, recurrent wheeze and AD was 1.14 (95% CI: 0.96-1.37), 1.37 (95% CI: 1.05-1.77), and 1.03 (95% CI: 0.81-1.31), respectively, for first-born infants of mothers employed in child-care institutions compared with infants of mothers not so employed. There was no effect of maternal employment in child-care institutions among infants with older siblings. In conclusion, the results did not support the hypothesis that maternal microbial exposure before or during pregnancy as reflected by maternal employment in child-care institutions protects the offspring against infant wheeze and AD.

Nutrition in pediatric lung disease

The respiratory system exists in an oxygenated milieu and is recurrently exposed to both endogenous and exogenous oxidants and irritants. A variety of dietary-dependent defenses have evolved to protect the lungs. These comprise vitamins, proteins, polyphenols, fatty acids and co-factors. This is a brief review of oxidant sources and the antioxidant system, as pertains to the respiratory system. The challenge to both clinicians and investigators is to understand how defenses are integrated and coordinated so that enhanced protection can be delivered.

The child with recurrent respiratory infections: normal or not?

Respiratory infections (RI) are one of the major complaints in children and adolescents, and represent a demanding challenge for the pediatrician. It has been estimated that at least 6% of Italian children younger than 6 yr of age present recurrent respiratory infections (RRI). Children with RRI are not affected by severe alterations of the immune system. RRI represent essentially the consequence of an increased exposure to infectious agents during the first years of life, when immune functions are still largely immature. Several social and environmental factors, such as day-care attendance, family size, air pollution, parental smoking, and home dampness, represent important risk factors for airway diseases and may contribute in various degrees to determine the incidence of RRI. The main problem for the pediatrician is to discriminate normal children with high RI frequency related to an augmented exposure to environmental risk factors from children affected by other underlying pathological conditions (immunological or not), predisposing to infectious diseases. When RRI diagnosis has been formulated, removal of environmental risk factors (i.e. precocious day-care attendance, smoking in the household) must first be suggested.

Socioeconomic status and health: youth development and neomaterialist and psychosocial mechanisms

There is substantial debate in the field of epidemiology over the theoretical underpinnings of socioeconomic status (SES)-disease mechanisms in the developed world. In particular, it has been debated whether psychosocial mechanisms are important in understanding these relationships, compared with material influences. Within an interdisciplinary context, this review synthesizes the youth development and resilience literatures in examination of this hypothesis. This review provides evidence that both classes of mechanisms are critical to understanding and addressing SES-disease mechanisms over the lifecourse. Research findings demonstrating the effects of these classes of factors point to the complicated and dynamic nature of how SES may impact disease. In the epidemiologic literature, investigators predominantly consider the cumulative impact of biological insults over time. A developmental perspective, however, provides evidence of the importance of psychosocial influences early in life on socioeconomic and health trajectories over the lifecourse. Future epidemiologic research should consider cumulative and developmental influences of early adversity--both psychosocial and material--on later health. This perspective may be particularly relevant to appropriately evaluating the impact of selection and causation in research on SES and disease and will also hopefully provide clarity to this ongoing theoretical debate.

Global pediatric environmental health

Children are uniquely vulnerable to environmental health problems. Developed countries report as the most common problems ambient (outdoor) air pollution and lead. Developing countries have a wider range of common problems, including childhood injuries, indoor air pollution, infectious disease, and poor sanitation with unsafe water. Globally, the agencies of the United Nations act to protect children and perform essential reporting and standards-setting functions. Conditions vary greatly among countries and are not always better in developing countries. Protecting the health of children requires strengthening the public health and medical systems in every country, rather than a single global agenda.

Asthma exacerbations. 2: aetiology

The natural history of asthma involves relatively stable periods that are often punctuated by significant exacerbations of symptoms. There are many aetiologies that may lead to an increase in asthma severity including respiratory infection (bacterial/viral), allergens, irritants, and occupational exposures. Each trigger probably acts through different mechanisms, but a final common pathway of multicellular inflammation, enhanced bronchial responsiveness, and airflow obstruction is a likely consequence. This review discusses the most common causes of asthma exacerbations with a focus on their microbiology and immunopathogenesis. Through an understanding of underlying causes of asthma exacerbations, treatments with increased effectiveness may be developed, and it is these future developments that may directly influence the morbidity and mortality of the disease.