Multimodel precipitation responses to removal of U.S. sulfur dioxide emissions

Emissions of aerosols and their precursors are declining due to policies enacted to protect human health, yet we currently lack a full understanding of the magnitude, spatiotemporal pattern, statistical significance, and physical mechanisms of precipitation responses to aerosol reductions. We quantify the global and regional precipitation responses to U.S. SO₂ emission reductions using three fully coupled chemistry-climate models: Community Earth System Model version 1, Geophysical Fluid Dynamics Laboratory Coupled Model 3, and Goddard Institute for Space Studies ModelE2. We contrast 200 year (or longer) simulations in which anthropogenic U.S. sulfur dioxide (SO₂) emissions are set to zero with present-day control simulations to assess the aerosol, cloud, and precipitation response to U.S. SO₂ reductions. In all three models, reductions in aerosol optical depth up to 70% and cloud droplet number column concentration up to 60% occur over the eastern U.S. and extend over the Atlantic Ocean. Precipitation responses occur both locally and remotely, with the models consistently showing an increase in most regions considered. We find a northward shift of the tropical rain belt location of up to 0.35° latitude especially near the Sahel, where the rainy season length and intensity are significantly enhanced in two of the three models. This enhancement is the result of greater warming in the Northern versus Southern Hemispheres, which acts to shift the Intertropical Convergence Zone northward, delivering additional wet season rainfall to the Sahel. Two of our three models thus imply a previously unconsidered benefit of continued U.S. SO₂ reductions for Sahel precipitation.

[A clinical case of occupational allergy to piperacilline. A novel diagnostic method: basophil activation test (BAT)]

BACKGROUND

Piperacillin, unlike other antibiotics, rarely causes immediate allergic reactions. Only two cases related to occupational exposure are reported in the literature.

OBJECTIVES

Adoption of new methods for diagnosis of occupational allergy to drugs.

METHODS

An atopic nurse, aged 30 years, was referred to our hospital for an allergic work-related reaction to piperacillin. The patient had suffered two successive episodes with immediate cutaneous reaction, angioedema and dyspnoea after preparing piperacillin. Almost four years previously she had suffered from similar symptoms after taking amoxicillin. She was submitted to a clinical examination and a routine allergic test, performing also specific IgE (Phadia Pharmacia ImmunoCap) and BAT (Basophil Activation Test) for Beta-lactam antibiotics.

RESULTS

A positive response to piperacillin was observed in our case using BAT a new non-invasive and safe method, that proved useful for diagnosis of allergy. Moreover, we observed a change from an allergic reaction for therapeutic use of amoxicillin to a work-related adverse reaction to another beta-lactam, piperacillin.

CONCLUSIONS

In previous clinical cases cutaneous and specific challenge tests were performed for diagnosis. At present, availability of an in vitro test, such as BAT may provide new diagnostic opportunities, and a useful tool for studying clinical cases other than, in perspective, monitoring exposed workers. Preventive measures were taken in the workplace to lower the risk of sensitization and allergic response. The nurse was transferred to a well controlled job.

[The allergic risk in agriculture: current situation and specific high-risk areas]

Contradictory aspects apparently coexist in relation to the causes of bronchial allergic inflammation in agriculture. It's worth notion that either exposure to inhalable dust and endotoxins or exposure to molecular patterns play a role in such a pathology; in particular endotoxins should protect against the onset of allergic diseases. Likewise, the exposure to pesticides would not lead to allergic asthma, but could facilitate the onset of pollinosis and contact dermatitis in gardeners. Moreover, the risk of anaphylaxis from bee sting would be lower in repeatedly bitten beekeepers if compared to sensitized and less exposed population, while atopy by itself is not evaluable as a risk factor for sensitization to hymenoptera. In conclusion either frequency and strength of exposure or distinctive feature of the subject are able to determine the occurrence of allergic disease in an almost different manner.

[Drug allergy: new methodological approaches in occupational clinical evaluations]

Drug reactions in pharmaceutical industry workers represent a quiet different problem in terms of evaluation and job ability, if related to hospitalized patients with adverse reaction to drug administration. The modern approach of GRADE (Grading Recommendation Assessment Development and Evaluation) was applied to 8 workers who had suspected occupational drug reactions, and were clinically examined in order to exclude any possible adverse event. Such a method allows to draw the relationship between adverse reaction to drugs, aetiology, risk evaluation and clinical events. Therefore, the adverse events are classified in type A (incongruous exposure), type B (hypersensitivity reactions) and not A not B (not work related). Both medical history/clinical evaluation and GRADE seem to give a correct view of the single case. Moreover, a high score suggests an occupational pathology, whilst low scores for evidence of drug reaction and occupational risk can avoid the use of diagnostic procedures.

[Occupational asthma: an underestimated pathology ]

The occupational allergens are estimated to determine 1 out 10 cases of asthma in adult workers. In Italy very low cases are compensated by the Italian National Insurance Against Professional Disease (INAIL), that legally recognized 90 cases in 1996 and only 9 cases in 2000. A real negative trend in making diagnosis and compensating workers for occupational asthma is due to three main causes. (1) Delayed diagnosis. Lack of protocols or lack of accuracy in applying them. Scarce collaboration of the general practitioners. (2) Unsatisfactory bill on compensation that misunderstands moderate asthma under drug control and asthma with scarce symptoms and occasional therapy. (3) Lack of prevention in industrial medicine. Occupational doctors play a role more relevant in legal activities than in clinical ones.

[Occupational allergic "march". Rapid evolution of contact dermatitis to ammonium persulfate into airborne contact dermatitis with rhinitis and asthma in a hairdresser]

BACKGROUND

Hairdressers are exposed to irritants and allergenic compounds that may cause contact dermatitis, rhinitis and asthma.

OBJECTIVES

In this paper we describe the case of a female, age 33 years, who developed contact dermatitis after 10 years of exposure to ammonium persulfate.

METHODS

After 7 months of progressively extensive and persistent skin lesions, respiratory symptoms appeared that were related to the occupational exposure (on-off test). SIDAPA and specific occupational patch test for hairdressers and occupational challenge with ammonium persulfate were performed. Clinical parameters of inflammation, ECP (eosinophil cationic protein) and exhaled nitric oxide (FeNO) were detected before and after the specific bronchial challenge.

RESULTS

The patch test was positive to ammonium persulfate (++), and bronchial challenge for ammonium persulfate showed a significant late response (FEV1 decrease--33%). Both FeNO and ECP showed a significant increase after 24 hours. Dermatitis, urticaria and angioedema occurred on the uncovered skin due to airborne contact. Topic steroids and anti-histaminic drugs resolved the clinical symptoms.

CONCLUSIONS

Bronchial challenge is, in fact, considered to be the gold standard for the diagnosis of occupational asthma, although new inflammatory parameters can contribute to the diagnosis and can be useful for monitoring after a specific inhalation test with occupational agents. The described case summarizes the evolution from contact dermatitis to inhalation allergy, suggesting the occurrence of an allergic "march" for occupational allergy.

[Consensus Document. Update on latex exposure and use of gloves in Italian health care settings]

This consensus document was prepared by an Italian working group including occupational health professionals involved for many years in the management of glove- and latex-related problems in health care settings. The aim of this document was to address the most significant technical, epidemiological, clinical, environmental and prevention problems related to the use of gloves and latex. The group's recommendations are based on scientific evidence and practical experience but they cannot be considered as final. These topics need to be periodically revised. The following points should be taken into account: glove quality seems to have improved considerably but the information on glove features provided by the manufacturers is often still inaccurate or incomplete; the regulations in force provide that the manufacturers perform tests to supply evidence for the quality of the products but they do not indicate which analytical method should be used and they do not require that the results be reported in the technical data sheets. Thus the manufacturers have only to declare that their products are "in accordance with the rules"; therefore, purchasers should require the manufacturing companies to supply detailed information and verify their reliability. Moreover, the rules should be adapted to higher quality standards; occupational physicians must be involved for the correct choice and purchase of protective gloves; the use of gloves (in particular latex gloves) and latex devices in health care settings should be based on specific criteria: procedures must be available stating which kind of gloves are suitable for specific tasks. When exposure to latex cannot be avoided it is necessary to choose products that have good biocompatibility (e.g., powder free-gloves with low allergen content); once and for all latex powdered gloves should no longer be commercially available! labels for latex devices (including gloves) should report the extractable latex allergen content. Limit values for extractable latex allergens should be established; the use of synthetic rubber gloves should be encouraged since some materials (e.g., neoprene and nitrile rubber) appear to have physical properties and protective efficacy similar to latex, plus good biocompatibility; more studies should be promoted to verify the protective efficacy of new synthetic materials; health care workers should be informed about the advisability and usefulness of using materials other than latex; health care services should not cause additional risks but rather highlight the advantages for workers and patients if the use of latex gloves and devices is minimized.

[Respiratory allergy to nickel. Description of an atypical clinical case]

BACKGROUND

Exposure to nickel sulphate, other than contact dermatitis, can potentially cause respiratory symptoms. Although few cases of occupational rhinitis and asthma are reported in literature, a prolonged exposure can determine sensitization and evolution to respiratory symptoms.

OBJECTIVES

Clinical evaluation of a case of occupational rhinitis and asthma due to nickel sulphate.

METHODS

A female worker, aged 43 years, has been occupationally exposed to nickel for 22 years. After 1 year she experienced asthma, apparently not work related. She treated the respiratory symptoms for many years, but a slow and progressive increase of the disease was observed. During the last five years a straight relationship between work and symptoms was observed. On-off test was positive. The diagnosis of occupational respiratory disease was based on the work-related symptoms and the specific nasal challenge test result.

RESULTS

An early response was observed with nasal symptoms (score 4), increase of anterior nasal airflow resistance (33%), severe dyspnea, haematic eosinophilia, and fall in FEV-1 of 18%.

CONCLUSIONS

The prolonged exposure to nickel determined impairment of respiratory function. Nasal challenge, more safe and useful than bronchial challenge, can be considered gold standard for the diagnosis of occupational rhinitis and asthma due to occupational allergens.

[Monitoring latex risk: detection of airborne and glove allergens]

BACKGROUND

Latex is a relevant occupational and environmental allergen, strongly related to the extensive use of natural rubber products.

OBJECTIVES

Threshold Limit Values have to be identified, as well as biocompatible materials in order to avoid sensitization or appearance of allergic symptoms.

METHODS

In this paper we consider the main methods, which have been used to detecting latex allergens for environmental monitoring of airborne and latex products.

RESULTS

We report our experience in such afield, and our approach to the latex problem, suggesting that quantification of allergens, which is currently applicable according to well standardized methods, should be adopted by manufacturers, agency and consumer organization.

The possible role of cockroaches in baker's asthma

BACKGROUND

Baker's asthma is related to wheat flour exposure and to other cereal dust exposure.

OBJECTIVES

The cockroach is considered a significant allergen and can occasionally trigger asthma in bakery workers.

METHODS

The case of a 33-year-old male, suffering from asthma in the workplace with previous equivocal tests for cereal dust was investigated Clinical assessment of the worker consisted of cutaneous and blood screening for common and occupational allergens, including cockroach. The subject was monitored for aspecific bronchial reactivity and peak flow in a cockroach disinfected workplace, and these data were compared to data obtained after previous workplace exposure.

RESULTS

The worker was not allergic to wheat and other cereal dusts or alpha-amylase, but was sensitized to cockroach. His asthmatic symptoms disappeared, and bronchial reactivity varied after a long period outside the bakery workplace. PEF monitoring, that had showed diurnal variability > 20% and differences between working and non-working periods, demonstrated both normal values and daily variations less than 10% when he returned to the cockroach disinfected workplace.

CONCLUSIONS

The cockroach is a common allergen, however no case of work-related baker's asthma due to the cockroach has been previously described. Clinical history and analysis of the allergens at the workplace must direct the clinical approach of the investigators, in order to correctly evaluate the subject and enable him/her to resume work.

[Occupational asthma due to cyanoacrylate: a case-report]

BACKGROUND

An increased use of acrylic compounds is observed in different industries, home repairs and hobbies. These compounds are known to cause skin sensitisation, irritation of mucous membranes and bronchial asthma. Methyl cyanoacrylate is moderately likely to be a sensitizer, while ethyl cyanoacrylate might be a weak sensitizer.

OBJECTIVES

Clinical evaluation of a case of occupational asthma due to cyanoacrylate.

METHODS

A female worker, aged 32 years, used ethyl cyanoacrylate daily. After 2 months she experienced dry cough and shortness breath. Some weeks later she developed bronchial asthma. The diagnosis of occupational asthma was based on the work-related symptoms and the inhalation challenge test result.

RESULTS

A late asthmatic response was observed with a maximum fall in FEV1 of 26% 345 minutes after exposure. Complete clinical and functional recovery was observed after inhalation of a broncho-dilating agent.

CONCLUSIONS

Acrylates are new occupational sensitising agents, causing rhinitis and asthma. It is not possible to perform prick tests or specific IgE measurements for these compounds. The bronchial challenge test is therefore the sole valid test for the diagnosis of occupational asthma.

Features and severity of occupational asthma upon diagnosis: an Italian multicentric case review

BACKGROUND

The severity of occupational asthma (OA) at the time of diagnosis is not known. In this study we aimed to evaluate some features of the disease at the time of diagnosis, particularly looking at severity and treatment before diagnosis.

METHODS

Medical records of subjects (n = 197) who had received a diagnosis of OA in six specialized centres of Northern and Central Italy in the period 1992-97 were reviewed. The severity of the disease at the time of diagnosis was determined on the basis of symptoms, peak expiratory flow (PEF, percentage predicted), forced expiratory volume in one second (FEV1, percentage predicted), and PEF variability, following the criteria of the National Institutes of Health and World Health Organizaton (NIH/WHO) guidelines on asthma. Medications used in the month before diagnosis were recorded.

RESULTS

The most common etiological agents were isocyanates (41.6%), flours (19.8%), woods (9.7%) and natural rubber latex (7.6%). The level of asthma severity (AS) was mild intermittent in 23.9% patients, mild persistent in 28.9%, moderate in 41.6%, and severe in 5.6%. Asthma severity was positively associated with current or previous smoking (P < 0.05), and was not related to atopy and current exposure. A relationship with bronchial reactivity to methacholine was shown in subjects at work. Treatment before diagnosis was consistent with the NIH/WHO guidelines in only 13.2% patients, whereas 75.6% were undertreated and 11.2% were overtreated.

CONCLUSIONS

In this study we found that the majority of patients had mild asthma at the time of diagnosis and that cigarette smoking was associated with a greater severity. Moreover, the majority of patients were undertreated before etiological diagnosis.

[Latex protein allergy and preventive measures]

Numerous studies and documents have been recently produced on the topic of latex allergy but the unpredictable nature of the clinical reactions and the widespread use of natural rubber products in health care has led to incorrect use due to inadequate risk assessment. This article is intended to supply a clinical and epidemiological outline of latex allergy and its management and prevention. The aim is to promote communication between specialists in various disciplines in order to protect patients and health care workers from the risk of latex allergy. The feasibility analysis of a latex-free stream in a hospital was made by a board composed of an allergist, occupational health physicians, a surgeon and an anaesthetician to evaluate the various phases of the project. The equipment available at the hospital (certified latex-free materials to equip pre and post operation trolleys, latex free gloves) and a correct work organization (definition and work procedures, check list of materials, alarm bracelet, warning signals) will make it possible to achieve a latex-free stream for symptomatic and sensitized patients at risk. The use of non-powdered gloves with low levels of protein residue, particularly in areas like operating theatres, can minimise the occurrence of sensitization to latex, protecting health care workers from serious consequences. Also, such measures reduce the cost of health surveillance, allow latex-safe areas to be maintained which can be inter-connected so that the best possible management ot latex-allergic patients during hospitalization is ensured.

[Sampling of airborne allergens: practical experience]

The availability of specific monoclonal and policlonal antibodies and the standardization of allergen extracts enables to quantify the exposure to airborne allergens in the domestic environment and at the workplace. In this article we report our experience coming from three studies based upon the measurement of airborne allergens in different environments. In a pharmaceutical factory we measured levels of laboratory animals allergens and evaluated the prevalence of sensitization to the same allergens among the workers. Airborne latex allergens and latex allergens content in latex gloves were measured in hospitals. In bakeries we evaluated the prevalence of sensitization to flour and measured flour allergens levels. The results of our studies give information useful to improve methods of prevention, diagnosis, and therapy of occupational allergic diseases.

Sensitization to the major allergen of Brazil nut is correlated with the clinical expression of allergy

BACKGROUND

Only a few studies have investigated the clinical role of food allergens, especially the relationship between sensitization to a given allergen and occurrence of adverse reactions when eating the relevant food item.

OBJECTIVE

This study evaluated the clinical role of the allergens of Brazil nut by comparing the patterns of IgE binding in sera from 11 patients with anaphylaxis after eating Brazil nuts with those from 10 subjects with no symptoms to this food item. Both groups had specific IgE to Brazil nut.

METHODS

Allergens in the in-house extract of Brazil nut were identified by SDS-PAGE/immunoblotting, the major allergen was purified by HPLC, and its N-terminal sequence was determined by a protein sequencer.

RESULTS

SDS-PAGE/immunoblotting detected a number of allergenic components with molecular weights ranging from 4 to 58 kd. All sera from symptomatic patients recognized a 9-kd allergen corresponding (as established by amino acid sequencing) to a 2S albumin already described as a major allergen of Brazil nut, whereas the other allergens each bound IgE from less than 50% of sera. No sera from asymptomatic subjects showed IgE binding to the 9-kd allergen, but they did recognize components from 25 to 58 kd, which are minor allergens.

CONCLUSIONS

These findings indicate that the allergen underlying clinical reactions to Brazil nut is a 2S albumin of 9 kd and that in vitro reactivity to this allergen identifies subjects who react in vivo to ingestion of this food.

[Occupational respiratory allergopathies: environmental monitoring, air allergens, prevention]

The prevalence of allergic diseases has increased over recent years. Several epidemiological studies have been undertaken to determine the prevalence and the incidence of asthma and/or rhinitis caused by occupational allergens, and to investigate the factors that may affect their occurrence. In the last decade, with the development of methods to measure airborne allergens concentrations. Studies have been undertaken to examine the relationship between the levels of airborne allergens and the development of symptoms. In this paper we have reviewed the main studies published on the topic, and focused our attention on three aeroallergens (wheat flour proteins, latex and laboratory animal allergens), that have been thoroughly investigated in literature, from both clinical, epidemiological and laboratory aspects, which highlighted the major responsible allergens and tried to set up the dose-response relationship for symptoms and for sensitization. These studies cannot be directly compared to each other because of differences in the methods; however they seem to suggest that low levels of airborne allergens may be sufficient to sensitize individuals. In contrast, the evidence for a dose-response relationship between exposure and symptoms is indirect and not always clear. Further epidemiological studies are necessary. In occupational medicine the presence of asthma or of another allergic disease in a severe form is suggested as a criterion for excluding workers from their job. Workers that do not manifest allergic symptoms but are atopic should be informed about the risk of developing occupational respiratory diseases, and periodic check-ups are strongly recommended. Medical controls must not be disconnected from environmental controls. Standardized methods of measurement of airborne allergens for environmental control need to be set in order to allow comparison between studies and to adopt primary prevention measures.

[Methods and applications in the control of hypersensitivity in exposed occupational populations]

The aim of this work is to present a clinical questionnaire for epidemiological studies in occupational allergology. We have evaluated and tested the items of such a questionnaire, finding a good sensitivity and specificity in terms of identification of symptoms and a clinical approach to the patient. The questionnaire was blind tested by two specialists and their results were found to be concordant. We realized that such a questionnaire is an easy instrument to use for medical personnel, reproducible and reliable. It can be applied in well orientated studies of occupational medicine as a first step in the investigation of work-related symptoms and in monitoring the workplace.