EAACI guidelines on environmental science for allergy and asthma: The impact of short-term exposure to outdoor air pollutants on asthma-related outcomes and recommendations for mitigation measures.

The EAACI Guidelines on the impact of short-term exposure to outdoor pollutants on asthma-related outcomes provide recommendations for prevention, patient care and mitigation in a framework supporting rational decisions for healthcare professionals and patients to individualize and improve asthma management and for policymakers and regulators as an evidence-informed reference to help setting legally binding standards and goals for outdoor air quality at international, national and local levels. The Guideline was developed using the GRADE approach and evaluated outdoor pollutants referenced in the current Air Quality Guideline of the World Health Organization as single or mixed pollutants and outdoor pesticides. Short-term exposure to all pollutants evaluated increases the risk of asthma-related adverse outcomes, especially hospital admissions and emergency department visits (moderate certainty of evidence at specific lag days). There is limited evidence for the impact of traffic-related air pollution and outdoor pesticides exposure as well as for the interventions to reduce emissions. Due to the quality of evidence, conditional recommendations were formulated for all pollutants and for the interventions reducing outdoor air pollution. Asthma management counselled by the current EAACI guidelines can improve asthma-related outcomes but global measures for clean air are needed to achieve significant impact.

The impact of outdoor pollution and extreme temperatures on asthma-related outcomes: A systematic review for the EAACI guidelines on environmental science for allergic diseases and asthma.

Air pollution is one of the biggest environmental threats for asthma. Its impact is augmented by climate change. To inform the recommendations of the EAACI Guidelines on the environmental science for allergic diseases and asthma, a systematic review (SR) evaluated the impact on asthma-related outcomes of short-term exposure to outdoor air pollutants (PM2.5, PM10, NO2, SO2, O3, and CO), heavy traffic, outdoor pesticides, and extreme temperatures. Additionally, the SR evaluated the impact of the efficacy of interventions reducing outdoor pollutants. The risk of bias was assessed using ROBINS-E tools and the certainty of the evidence by using GRADE. Short-term exposure to PM2.5, PM10, and NO2 probably increases the risk of asthma-related hospital admissions (HA) and emergency department (ED) visits (moderate certainty evidence). Exposure to heavy traffic may increase HA and deteriorate asthma control (low certainty evidence). Interventions reducing outdoor pollutants may reduce asthma exacerbations (low to very low certainty evidence). Exposure to fumigants may increase the risk of new-onset asthma in agricultural workers, while exposure to 1,3-dichloropropene may increase the risk of asthma-related ED visits (low certainty evidence). Heatwaves and cold spells may increase the risk of asthma-related ED visits and HA and asthma mortality (low certainty evidence).

The impact of exposure to tobacco smoke and e-cigarettes on asthma-related outcomes: Systematic review informing the EAACI guidelines on environmental science for allergic diseases and asthma.

To inform the clinical practice guidelines' recommendations developed by the European Academy of Allergy and Clinical Immunology systematic reviews (SR) assessed using GRADE on the impact of environmental tobacco smoke (ETS) and active smoking on the risk of new-onset asthma/recurrent wheezing (RW)/low lung function (LF), and on asthma-related outcomes. Only longitudinal studies were included, almost all on combustion cigarettes, only one assessing e-cigarettes and LF. According to the first SR (67 studies), prenatal ETS increases the risk of RW (moderate certainty evidence) and may increase the risk of new-onset asthma and of low LF (low certainty evidence). Postnatal ETS increases the risk of new-onset asthma and of RW (moderate certainty evidence) and may impact LF (low certainty evidence). Combined in utero and postnatal ETS may increase the risk of new-onset asthma (low certainty evidence) and increases the risk of RW (moderate certainty evidence). According to the second SR (24 studies), ETS increases the risk of severe asthma exacerbations and impairs asthma control and LF (moderate certainty evidence). According to the third SR (25 studies), active smoking increases the risk of severe asthma exacerbations and of suboptimal asthma control (moderate certainty evidence) and may impact asthma-related quality-of-life and LF (low certainty evidence).

The impact of indoor pollution on asthma-related outcomes: A systematic review for the EAACI guidelines on environmental science for allergic diseases and asthma.

Systematic review using GRADE of the impact of exposure to volatile organic compounds (VOCs), cleaning agents, mould/damp, pesticides on the risk of (i) new-onset asthma (incidence) and (ii) adverse asthma-related outcomes (impact). MEDLINE, EMBASE and Web of Science were searched for indoor pollutant exposure studies reporting on new-onset asthma and critical and important asthma-related outcomes. Ninety four studies were included: 11 for VOCs (7 for incidenceand 4 for impact), 25 for cleaning agents (7 for incidenceand 8 for impact), 48 for damp/mould (26 for incidence and 22 for impact) and 10 for pesticides (8 for incidence and 2 for impact). Exposure to damp/mould increases the risk of new-onset wheeze (moderate certainty evidence). Exposure to cleaning agents may be associated with a higher risk of new-onset asthma and with asthma severity (low level of certainty). Exposure to pesticides and VOCs may increase the risk of new-onset asthma (very low certainty evidence). The impact on asthma-related outcomes of all major indoor pollutants is uncertain. As the level of certainty is low or very low for most of the available evidence on the impact of indoor pollutants on asthma-related outcomes more rigorous research in the field is warranted.

A call from 40 public health scientists for an end to the continuing humanitarian and environmental catastrophe in Gaza.

An under-recognised aspect of the current humanitarian catastrophe in Gaza is the impact of the war on the environment and the associated risks for human health. This commentary contextualises these impacts against the background of human suffering produced by the overwhelming violence associated with the use of military force against the general population of Gaza. In calling for an immediate cessation to the violence, the authors draw attention to the urgent need to rebuild the health care system and restore the physical and human infrastructure that makes a liveable environment possible and promotes human health and well-being, especially for the most vulnerable in the population. Environmental remediation should therefore form one of the most important parts of international efforts to assist reconstruction, through which we hope Palestinians and Israelis will achieve lasting peace, health, and sustainable development, all as part of accepted international human rights obligations.

Is exposure to pollen a risk factor for moderate and severe asthma exacerbations?

Limited number of studies have focused on the impact of pollen exposure on asthma. As a part of the EAACI Guidelines on Environment Science, this first systematic review on the relationship of pollen exposure to asthma exacerbations aimed to bridge this knowledge gap in view of implementing recommendations of prevention. We searched electronic iPubMed, Embase, and Web of Science databases using a set of MeSH terms and related synonyms and identified 73 eligible studies that were included for systemic review. When possible, meta-analyses were conducted. Overall meta-analysis suggests that outdoor pollen exposure may have an effect on asthma exacerbation, but caution is needed due to the low number of studies and their heterogeneity. The strongest associations were found between asthma attacks, asthma-related ED admissions or hospitalizations, and an increase in grass pollen concentration in the previous 2-day overall in children aged less than 18 years of age. Tree pollen may increase asthma-related ED visits or admissions lagged up to 7-day overall in individuals younger than 18 years. Rare data show that among subjects under 18 years of age, an exposure to grass pollen lagged up to 3 days may lower lung function. Further research considering effect modifiers of pollen sensitization, hay fever, asthma, air pollution, green spaces, and pre-existing medications is urgently warranted to better evaluate the impacts of pollen on asthma exacerbation. Preventive measures in relation to pollen exposure should be integrated in asthma control as pollen increase continues due to climate change.

Occupational risk factors and exposure-response relationships for airway disease among health workers exposed to cleaning agents in tertiary hospitals.

OBJECTIVES: This study investigated occupational risk factors and exposure-response relationships for airway disease among health workers (HWs) exposed to cleaning agents in two tertiary hospitals in South Africa and Tanzania. METHODS: In this cross-sectional study, 697 participants completed questionnaire interviews while 654 underwent fractional exhaled nitric oxide (FeNO) testing. Asthma Symptom Score (ASS) was computed based on the sum of answers to five questions on asthma-related symptoms in the past 12 months. For exposure-response analyses, cleaning agent-related self-reported exposure variables were categorised into three levels (cleaning product not used; use of a cleaning product for up to 99 min per week and use of a cleaning product for ≥100 min per week). RESULTS: Asthma-related outcomes (ASS and FeNO) demonstrated positive associations with medical instrument cleaning agents (orthophthalaldehyde and enzymatic cleaners) and tasks (instruments precleaning and changing sterilisation solutions) as well as patient care activities (disinfection prior to procedures and disinfecting wounds). A particularly pronounced dose-response relationship was observed between work-related ocular-nasal symptoms and medical instrument cleaning agents (orthophthalaldehyde, glutaraldehyde, enzymatic cleaners, alcohols and bleach) (OR range: 2.37-4.56) and tasks (OR range: 2.92-4.44). A strong association was also observed between ASS and use of sprays for fixed surface cleaning (mean ratio 2.81; 95% CI 1.41 to 5.59). CONCLUSIONS: Specific agents for medical instrument disinfection for example, orthophthalaldehyde and enzymatic cleaners, patient care activities and use of sprays are important occupational risk factors for airway disease among HWs.

Prevalence of work-related skin symptoms and associated factors among tertiary hospital workers exposed to cleaning agents in Southern Africa.

INTRODUCTION: Working with cleaning products is associated with occupational contact dermatitis in health workers (HWs), but information on predictors for these outcomes is limited. OBJECTIVES: This study investigated the prevalence of work-related skin symptoms (WRSS) and associated factors in HWs exposed to cleaning agents in two Southern African tertiary hospitals. METHODS: A cross-sectional study of 697 HWs used an interviewer-administered questionnaire and assessed for atopy using Phadiatop. RESULTS: HWs' median age was 42 years, 77.0% were female and 42.5% were atopic. The prevalence of WRSS in the last 12 months was 14.8%, 12.3% had probable contact dermatitis (PCD) and 3.2% had probable contact urticaria (PCU). Technicians (ORadj 3.91) and tasks involving cleaning and disinfection of skin wounds (ORadj 1.98) were associated with WRSS in the past year. Factors associated with PCD included sterilizing instruments, disinfecting skin before procedures and use of wound adhesives. Factors associated with PCU included specimen preparation using formalin, medical instrument sterilization tasks, and skin/wound cleaning and disinfection. Appropriate glove use when performing patients' skin/wound care was protective against WRSS. CONCLUSIONS: Tasks involving cleaning and disinfecting patients' skin and wounds were associated with WRSS in HWs, especially when performed without gloves.

Current global perspectives on silicosis-Convergence of old and newly emergent hazards.

Silicosis not a disease of the past. It is an irreversible, fibrotic lung disease specifically caused by exposure to respirable crystalline silica (RCS) dust. Over 20,000 incident cases of silicosis were identified in 2017 and millions of workers continue to be exposed to RCS. Identified case numbers are however a substantial underestimation due to deficiencies in reporting systems and occupational respiratory health surveillance programmes in many countries. Insecure workers, immigrants and workers in small businesses are at particular risk of more intense RCS exposure. Much of the focus of research and prevention activities has been on the mining sector. Hazardous RCS exposure however occurs in a wide range of occupational setting which receive less attention, in particular the construction industry. Recent outbreaks of silicosis associated with the fabrication of domestic kitchen benchtops from high-silica content artificial stone have been particularly notable because of the young age of affected workers, short duration of RCS exposure and often rapid disease progression. Developments in nanotechnology and hydraulic fracking provide further examples of how rapid changes in technology and industrial processes require governments to maintain constant vigilance to identify and control potential sources of RCS exposure. Despite countries around the world dealing with similar issues related to RCS exposure, there is an absence of sustained global public health response including lack of consensus of an occupational exposure limit that would provide protection to workers. Although there are complex challenges, global elimination of silicosis must remain the goal.

Work-related allergy and asthma associated with cleaning agents in health workers in Southern African tertiary hospitals.

BACKGROUND: Health workers (HWs) are exposed to diverse cleaning agents in large hospitals. This study determined the prevalence of work-related symptoms, allergic sensitization, and lung function abnormalities in HWs of two tertiary hospitals in Southern Africa. METHODS: A cross-sectional study of 699 HWs (South Africa: SAH, n = 346; Tanzania: TAH, n = 353) was conducted. Health outcomes were assessed using a standardized ECRHS questionnaire, immunological tests (specific IgE antibody to common aero-allergens and to occupational allergens: natural rubber latex [NRL]  Hev b5 and Hev b6.02, chlorhexidine, and ortho-phthalaldehyde [OPA]), spirometry [pre-and post- bronchodilator], methacholine challenge, and fractional exhaled nitric oxide (FeNO). RESULTS: A large proportion of participants (78%) were women. Median age was 42 years, with 76% nurses, 12% cleaners, and 5% administrative workers. Current smoking was more common in SAHWs (12%) than TAHWs (1%). The overall prevalence of doctor-diagnosed asthma was 7%. Atopy was present in 43% of HWs, while 4% were sensitized to OPA, 2% to NRL, and 1% to chlorhexidine. Prevalence of work-related ocular-nasal symptoms (16%) was higher than skin (12%) and chest (7%) symptoms. TAHWs had significantly lower mean lung volumes, higher degrees of significant airflow obstruction and impaired lung function. The prevalence of bronchial hyperresponsiveness in SAHWs (14%) was high. Overall, 23% of HWs had abnormal FeNO; 6% having high (>50 ppb) levels. FeNO was positively associated with sensitization to occupational allergens, primarily OPA and NRL. CONCLUSIONS: HWs from both hospitals had similar prevalence of work-related respiratory symptoms. Sensitization to OPA and NRL appears to be contributing to allergic airway inflammation in these HWs.

COVID-19: a new burden of respiratory disease among South African miners?

PURPOSE OF REVIEW: Mineworkers in South Africa experience a triple burden of disease due to their distinct work experience. Silicosis increases their risk of tuberculosis (TB), exacerbated by the HIV epidemic. Work-related factors are likely to increase transmission, severity, and post infection sequelae of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Understanding these relationships is important to control the impact of the epidemic. RECENT FINDINGS: SARS-CoV-2 infection rates among mineworkers exceed the population rates in the provinces in which those mines are located. Migrant work, living in crowded hostels, working in narrow poorly ventilated shafts mainly underground constitute important factors that increase transmission risk. Mineworkers continue to experience high levels of silica exposure. The prevalences of silicosis, HIV and pulmonary TB, remain high. Interstitial lung disease, pulmonary TB, and HIV have all been associated with poorer outcomes of SARS-CoV-2 infections. Mineworkers with post infection respiratory sequelae are likely to lose their jobs or lose income, due to the physically demanding nature of underground minework. SUMMARY: Further research into the unique work-related risk factors in mining that influence the COVID-19 epidemic is crucial for optimizing current interventions. Reducing SARS-CoV-2 infection transmission, health monitoring of infected and vulnerable workers, and following up of postinfection outcomes is essential to protect the respiratory health of miners.

The neglected millions: the global state of aquaculture workers' occupational safety, health and well-being.

A scoping project was funded by the Food and Agriculture Organization in 2017 on the health and safety of aquaculture workers. This project developed a template covering basic types of aquaculture production, health and safety hazards and risks, and related data on injuries and occupational ill health, regulations, social welfare conditions, and labour and industry activity in the sector. Profiles using the template were then produced for key aquaculture regions and nations across the globe where information could be obtained. These revealed both the scale and depth of occupational safety and health (OSH) challenges in terms of data gaps, a lack of or poor risk assessment and management, inadequate monitoring and regulation, and limited information generally about aquaculture OSH. Risks are especially high for offshore/marine aquaculture workers. Good practice as well as barriers to improving aquaculture OSH were noted. The findings from the profiles were brought together in an analysis of current knowledge on injury and work-related ill health, standards and regulation, non-work socioeconomic factors affecting aquaculture OSH, and the role of labour and industry in dealing with aquaculture OSH challenges. Some examples of governmental and labour, industry and non-governmental organisation good practice were identified. Some databases on injury and disease in the sector and research initiatives that solved problems were noted. However, there are many challenges especially in rural and remote areas across Asia but also in the northern hemisphere that need to be addressed. Action now is possible based on the knowledge available, with further research an important but secondary objective.

The association between ambient NO2 and PM2.5 with the respiratory health of school children residing in informal settlements: A prospective cohort study.

BACKGROUND: No previous epidemiological study has investigated the combined association of long-term ambient nitrogen dioxide (NO2) and particulate matter of diameter size-2.5 (PM2.5) exposure with asthma outcomes among schoolchildren in Africa. OBJECTIVES: This study investigated the independent and co-pollutant association of long-term exposures to ambient air pollutants on asthma-associated outcomes in a cohort of schoolchildren in the Western Cape Province of South Africa. METHODS: A total of 590 grade-4 schoolchildren residing in four informal settlements were studied. Spirometry and fractional exhaled nitric-oxide (FeNO) measurements were conducted, including a standardized questionnaire administered to caregivers at baseline and 12-months follow-up. Annual NO2 and PM2.5 levels were estimated for each child's home using land-use regression modelling. Single- and two-pollutant models were constructed to assess the independent and co-pollutant association of both air pollutants (NO2 and PM2.5) on new cases of asthma-associated outcomes adjusting-for host characteristics, indoor exposures and study area. RESULTS: The annual average concentration of PM2.5 and NO2 were 10.01µg/m3 and 16.62µg/m3 respectively, across the four study areas, and were below the local Standards of 20µg/m3 and 40µg/m3, for both pollutants, respectively. In the two-pollutant-adjusted models, an interquartile range (IQR) increase of 14.2µg/m3 in NO2 was associated with an increased risk of new onset of ocular-nasal symptoms (adjusted odds ratio-aOR: 1.63, 95% CI: 1.01-2.60), wheezing (aOR: 3.57, 95% CI: 1.18-10.92), more than two or more asthma symptom score (aOR: 1.71, 95% CI: 1.02-2.86), and airway inflammation defined as FeNO > 35 ppb (aOR: 3.10, 95% CI: 1.10-8.71), independent of PM2.5 exposures. CONCLUSION: This study provided evidence that ambient NO2 levels below local standards and international guidelines, independent of PM2.5 exposure, increases new cases of asthma-associated outcomes after 12-months.

Assessing the health impact of interventions for baker's allergy and asthma in supermarket bakeries: a group randomised trial.

PURPOSE: To assess the impact of an intervention for baker's allergy and asthma in supermarket bakeries. METHODS: A group randomised trial conducted in 31 bakeries (n = 337 bakers) that were randomly assigned to one of two intervention groups (n = 244 bakers) and a control group (n = 93 bakers). Health data collected prior to and 1-year after the intervention included information obtained from an ECRHS questionnaire; tests for atopy and serum-specific IgE to cereal flours; fractional exhaled nitric oxide (FeNO). Data from the two intervention groups were combined to form one intervention group for purposes of the statistical analysis. RESULTS: At 1 year of follow-up, the incidence and level of decline of work-related ocular-nasal and chest symptoms, sensitisation status and elevated FeNO (FeNO > 25 ppb) was similar in both intervention and control groups. The mean FeNO difference was also similar across both groups (2.2 ppb vs 1.7 ppb, p = 0.86). In those with FeNO > 25 ppb at baseline, the decline was greater in the intervention compared to control group (16.9 ppb vs 7.7 ppb, p = 0.24). Multivariate logistic regression models (adjusting for smoking, baseline sensitisation to cereal flour, baseline FeNO > 25 ppb) did not demonstrate an appreciable FeNO decline (≥ 10%) in the intervention compared to control group. However, stratification by the presence of work-related ocular-nasal symptoms in bakers at baseline demonstrated a significant FeNO decline (≥ 10%) in the intervention compared to the control group (OR 3.73, CI 1.22-11.42). CONCLUSION: This study demonstrates some evidence of an intervention effect on FeNO 1 year after an intervention, particularly in bakers with work-related ocular-nasal symptoms.

Food processing and occupational respiratory allergy- An EAACI position paper.

Occupational exposure to foods is responsible for up to 25% of cases of occupational asthma and rhinitis. Animal and vegetable high-molecular-weight proteins present in aerosolized foods during food processing, additives, preservatives, antioxidants, and food contaminants are the main inhalant allergen sources. Most agents typically cause IgE-mediated allergic reactions, causing a distinct form of food allergy (Class 3 food allergy). The allergenicity of a food protein, allergen exposure levels, and atopy are important risk factors. Diagnosis relies on a thorough medical and occupational history, functional assessment, assessment of sensitization, including component-resolved diagnostics where appropriate, and in selected cases specific inhalation tests. Exposure assessment, including allergen determination, is a cornerstone for establishing preventive measures. Management includes allergen exposure avoidance or reduction (second best option), pharmacological treatment, assessment of impairment, and worker's compensation. Further studies are needed to identify and characterize major food allergens and define occupational exposure limits, evaluate the relative contribution of respiratory versus cutaneous sensitization to food antigens, evaluate the role of raw versus cooked food in influencing risk, and define the absolute or relative contraindication of patients with ingestion-related food allergy, pollinosis, or oral allergy syndrome continuing to work with exposure to aerosolized food allergens.

Asthma-related outcomes associated with indoor air pollutants among schoolchildren from four informal settlements in two municipalities in the Western Cape Province of South Africa.

The health impact of indoor air pollution in informal settlement households has not been extensively studied in South Africa. This cross-sectional study investigated the association between asthma and common indoor exposures among schoolchildren from four informal settlements located in two municipalities in the Western Cape Province. A total of 590 children, aged 9-11 years, were recruited. The International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire was administered to caregivers. Pulmonary function assessment included spirometry and fractional exhaled nitric oxide (FeNO). Phadiatop test for atopy was done. The prevalence of doctor-diagnosed asthma was 3.4% (n = 20) among whom only 50% were on treatment. The prevalence of current wheeze was 12.9%, and 17.6% had airway obstruction (FEV1  < lower limit of normal), while 10.2% had airway inflammation (FeNO > 35 ppb). In adjusted logistic regression models, dampness, visible mold growth, paraffin use for cooking, and passive smoking were associated with a twofold to threefold increased risk in upper and lower airway outcomes. The strongest association was that of visible mold growth with rhinitis (adjusted odds ratio-aOR 3.37, 95% CI: 1.69-6.71). Thus, there is a need for improved diagnosis of childhood asthma and Indoor Air Quality in informal settlement households.

Occupational asthma associated with bleached chlorine-free cellulose dust in a sanitary pad production plant.

BACKGROUND: Cellulose is an insoluble plant polysaccharide produced from soft-wood pulp. Although chronic respiratory effects associated with high cellulose-based dust levels have been previously described, occupational asthma has not. A 37 year old machine operator in a sanitary pad production factory presented with new-onset work-related asthma symptoms for two years. METHODS: The worker underwent clinical, pulmonological and immunological (skin prick tests, serum specific IgE determinations) evaluation using standardised procedures. The cellulose product was subjected to scanning electron microscopy (SEM) examination. A specific inhalation challenge test performed with the cellulose product ensured that dust concentrations were kept below 5 mg/m3 . RESULTS: The subject was not atopic and did not have elevated IgE to pine wood or xylanase. The cellulose product appeared to be free of protein contaminants on SEM. The Work Effect Index computed on serial PEF recordings was elevated (WEI = 3.8).Specific inhalational challenge with the cellulose product dust revealed a late bronchial response (39% drop in FEV1 at 3 hours post challenge). CONCLUSION: This is the first reported case of occupational asthma to a cellulose fibre product. A non-specific immune reaction or irritant response seems likely. These fibres may therefore not be biologically inert. The occupational exposure limit of 10 mg/m3 generally used for cellulose dust appears to be non-protective.

Risk factors associated with allergic sensitization and asthma phenotypes among poultry farm workers.

BACKGROUND: This study investigated the risk factors for occupational allergic sensitization and various asthma phenotypes in poultry-workers. METHODS: A cross-sectional study of 230 workers used a modified ECRHS questionnaire, spirometry, FeNO, Phadiatop, and sIgE to poultry farming related allergens. RESULTS: Worker's mean age was 37 ± 9 years, 68% male, 43% current-smokers, 34% atopic, and 5% casual-workers. The prevalence of non-atopic asthma (NAA = 7%) was higher than atopic-asthma (AA = 5%) and probable allergic occupational-asthma (OA = 3%). Sensitization to at least one poultry farming related allergen was 24%. Workers sensitized to chicken-specific-allergens were more likely to be atopic (ORunadj = 20.9, 95%CI: 4.7-93.2) or employed as casual-workers (ORunadj = 6.0, 95%CI: 1.1-35.9). Work-related chest symptoms were associated the rearing-department (ORadj = 3.2, 95%CI: 1.2-8.4) and exposure to high gas/dust/fumes (ORadj = 4.8, 95%CI: 2.4-9.5). Airflow reversibility (ORadj = 10.9, 95%CI: 2.0-60.3) was significantly associated with casual-work status. CONCLUSION: Allergic and non-allergic mechanisms play a role in asthma development among poultry-workers with casual workers demonstrating increased risk.

A prospective cohort study on ambient air pollution and respiratory morbidities including childhood asthma in adolescents from the western Cape Province: study protocol.

BACKGROUND: There is evidence from existing literature that ambient air pollutant exposure in early childhood likely plays an important role in asthma exacerbation and other respiratory symptoms, with greater effect among asthmatic children. However, there is inconclusive evidence on the role of ambient air pollutant exposures in relation to increasing asthma prevalence as well as asthma induction in children. At the population level, little is known about the potential synergistic effects between pollen allergens and air pollutants since this type of association poses challenges in uncontrolled real life settings. In particular, data from sub-Sahara Africa is scarce and virtually absent among populations residing in informal residential settlements. METHODS/DESIGN: A prospective cohort study of 600 school children residing in four informal settlement areas with varying potential ambient air pollutant exposure levels in the Western Cape in South Africa is carried-out. The study has two follow-up periods of at least six-months apart including an embedded panel study in summer and winter. The exposure assessment component models temporal and spatial variability of air quality in the four study areas over the study duration using land-use regression modelling (LUR). Additionally, daily pollen levels (mould spores, tree, grass and weed pollen) in the study areas are recorded. In the panel study asthma symptoms and serial peak flow measurements is recorded three times daily to determine short-term serial airway changes in relation to varying ambient air quality and pollen over 10-days during winter and summer. The health outcome component of the cohort study include; the presence of asthma using a standardised ISAAC questionnaire, spirometry, fractional exhaled nitric-oxide (FeNO) and the presence of atopy (Phadiatop). DISCUSSION: This research applies state of the art exposure assessment approaches to characterize the effects of ambient air pollutants on childhood respiratory health, with a specific focus on asthma and markers of airway inflammation (FeNO) in South African informal settlement areas by considering also pollen counts and meteorological factors. The study will generate crucial data on air pollution and asthma in low income settings in sub-Sahara Africa that is lacking in the international literature.

Environmental factors associated with baseline and serial changes in fractional exhaled nitric oxide (FeNO) in spice mill workers.

BACKGROUND: This study evaluated the determinants of high fractional exhaled nitric oxide (FeNO; >50 ppb) and serial changes in FeNO over a 24-hour period in spice mill workers at risk of work-related allergic respiratory disease and asthma. METHODS: A cross-sectional study of 150 workers used European Community Respiratory Health Survey (ECRHS) questionnaires, Phadiatop, serum-specific IgE (garlic, chilli pepper, wheat; Phadia, ImmunoCAP), spirometry and FeNO. A hand-held portable nitric oxide sampling device (NIOX MINO, Aerocrine AB) measured FeNO before and after the 8-hour shift and after 24 hours from baseline. RESULTS: The mean age of workers was 33 years; 71% were male, 46% current smokers and 45% atopic. Among workers with garlic sensitisation, 13% were monosensitised and 6% were co-sensitised to chilli pepper. Baseline preshift FeNO geometric mean (GM=14.9 ppb) was similar to the mean change across shift (GM=15.4 ppb) and across the 24-hour period (GM=15.8 ppb). In multivariate linear models, smoking (ß=-0.507) and atopy (ß=0.433) were strongly associated with FeNO. High FeNO (>50 ppb) was significantly associated with asthma-like symptoms due to spice dust (OR=5.38, CI 1.01 to 28.95). Sensitisation to chilli pepper was more strongly correlated with FeNO (r=0.32) and FeNO>50 ppb (OR=17.04, p=0.005) than garlic. FeNO increase (>12%) across 24 hours demonstrated a strong association with elevated exposures to spice dust particulate (OR=3.77, CI 1.01 to 14.24). CONCLUSIONS: This study suggests that chilli pepper sensitisation is associated with high FeNO (>50 ppb), more strongly compared with garlic, despite the low prevalence of sensitisation to chilli. Elevated inhalant spice dust particulate is associated with a delayed elevation of FeNO across the 24-hour period.