Urea formaldehyde insulating foams: a risk for health?

Summary In 1983, the media brought out articies expressing serious concerns as to the use of Urea Formaldehyde Foam Insulation (UFFI). The emission of formaldehyde vapours within UFF insulated homes was held responsible for ?serious health problems?. A major controversy then started, with on the one hand several consumer associations, and on the other, the UFFI raw materials producing companies, while government departments concerned were called upon to intervene. On careful consideration of facts, it clearly appeared that the number of health-related incidents that could be charged to UFFI was much smaller than uncontrolled rumour would indicate, and that the effects of formaldehyde, although very unpleasant, fortunately did not have the degree of severity reported. Establishing a dialogue between the parties involved seemed possible and a mutually acceptable solution, safegarding the interests of all concerned, within reach... UFFI could be used in homes provided it be implemented by skilled professionals who would accept to redress duly established insulation defects. Unfortunately, the anti-UFFI press campaign had ruined the image of the product in the mind of potential users. Industry gradually withdrew from the market. As for customers with defect ridden homes, they had no redress possibility left to them... Six years have elapsed since then, and it should now be possible to review the issue with a fresh and dispassionate mind, while assessing the causes and effects of the polemics of the past. UFFI is no longer used in France and may well not be for a long time yet, unless of course the value of an effective low cost insulation material well suited to existing buildings, is eventually rediscovered. In any event, it is unquestionably interesting to draw a lesson from this typical example and try to find better approaches to similar situations particularly in the housing sector, in order to best meet the requirements of all concerned.     

Respiratory response to formaldehyde and off-gas of urea formaldehyde foam insulation.

In 18 subjects, 9 of whom had previously complained of various nonrespiratory adverse effects from the urea formaldehyde foam insulation (UFFI) in their homes, pulmonary function was assessed before and after exposure in a laboratory. On separate occasions formaldehyde, 1 part per million (ppm), and UFFI off-gas yielding a formaldehyde concentration of 1.2 ppm, were delivered to each subject in an environmental chamber for 90 minutes and a fume hood for 30 minutes respectively. None of the measures of pulmonary function used (forced vital capacity, forced expiratory volume in 1 second or maximal midexpiratory flow rate) showed any clinically or statistically significant response to the exposure either immediately after or 8 hours after its beginning. There were no statistically significant differences between the responses of the group that had previously complained of adverse effects and of the group that had not. There was no evidence that either formaldehyde or UFFI off-gas operates as a lower airway allergen or important bronchospastic irritant in this heterogeneous population.     

Collaboration,not co-optation.

Studies of health effects of urea formaldehyde foam insulation (UFFI) were critically reviewed by means of accepted rules for evidence of causation. Three categories of health effects were examined: reported symptoms, primarily of the upper respiratory tract, lower respiratory tract disease and cancer. Most of the studies purporting to demonstrate health effects of UFFI failed to meet minimal methodologic criteria for evidence of causation. Evidence from the adequate studies provides little support for the hypothesis of a causative role of UFFI in health problems.     

Seasonal Changes in Endotoxin Exposure and Its Relationship to Exhaled Nitric Oxide and Exhaled Breath Condensate pH Levels in Atopic and Healthy Children

Endotoxin, a component of the cell walls of gram-negative bacteria, is a contaminant in organic dusts (house dust) and aerosols. In humans, small amounts of endotoxin may cause a local inflammatory response. Exhaled nitric oxide (eNO) levels, an inflammation indicator, are associated with the pH values of exhaled breath condensate (EBC). This study evaluated seasonal changes on indoor endotoxin concentrations in homes and the relationships between endotoxin exposure and eNO/EBC pH levels for healthy children and children with allergy-related respiratory diseases. In total, 34 children with allergy-related respiratory diseases and 24 healthy children were enrolled. Indoor air quality measurements and dust sample analysis for endotoxin were conducted once each season inside 58 surveyed homes. The eNO, EBC pH levels, and pulmonary function of the children were also determined. The highest endotoxin concentrations were on kitchen floors of homes of children with allergy-related respiratory diseases and healthy children, and on bedroom floors of homes of asthmatic children and healthy children. Seasonal changes existed in endotoxin concentrations in dust samples from homes of children with allergic rhinitis, with or without asthma, and in EBC pH values among healthy children and those with allergy-related respiratory diseases. Strong relationships existed between endotoxin exposure and EBC pH values in children with allergic rhinitis.     

Association between gas cooking and respiratory disease in children.

A four-year longitudinal study of the prevalence of respiratory symptoms and disease in schoolchildren and related environmental and socio-economic factors is in progress. We report results for the first year of this study (1973). A total of 5758 children aged 6 to 11 years from 28 randomly selected areas of England and Scotland were examined. In an analysis of the effects on health of possible indoor pollutants, boys and girls from homes in which gas was used for cooking were found to have more cough, "colds going to the chest", and bronchitis than children from homes where electricity was used. The girls also had more wheeze if their families used gas for cooking. This "cooking effect" appeared to be independent of the effects of age, social class, latitude, population density, family size, overcrowding, outdoor levels of smoke and sulphur dioxide and types of fuel used for heating. It was concluded that elevated levels of oxides of nitrogen arising from the combustion of gas might be the cause of the increased respiratory illness.     

Respiratory sequelae of whooping cough. Swansea Research Unit of the Royal College of General Practitioners.

Eight hundred and thirteen children who had had whooping cough when under 5 years of age in the 1977-9 epidemic were compared with a control group roughly four and a half years later, each child being matched by age and sex and from the same class in school. The index group showed long term respiratory sequelae of whooping cough--namely, deterioration in lung function, increase in respiratory symptoms, and increased admission to hospital for both upper and lower respiratory conditions. Asthma was significantly more common in the index group, suggesting that asthma was being regarded as a contraindication to pertussis vaccination. Only 3.5% of the asthmatic children in the index group had been vaccinated as against 29.1% of the controls.     

Aberrant Neuromagnetic Activation in the Motor Cortex in Children with Acute Migraine: A Magnetoencephalography Study

Migraine attacks have been shown to interfere with normal function in the brain such as motor or sensory function. However, to date, there has been no clinical neurophysiology study focusing on the motor function in children with migraine during headache attacks. To investigate the motor function in children with migraine, twenty-six children with acute migraine, meeting International Classification of Headache Disorders criteria and age- and gender-matched healthy children were studied using a 275-channel magnetoencephalography system. A finger-tapping paradigm was designed to elicit neuromagnetic activation in the motor cortex. Children with migraine showed significantly prolonged latency of movement-evoked magnetic fields (MEF) during finger movement compared with the controls. The correlation coefficient of MEF latency and age in children with migraine was significantly different from that in healthy controls. The spectral power of high gamma (65–150 Hz) oscillations during finger movement in the primary motor cortex is also significantly higher in children with migraine than in controls. The alteration of responding latency and aberrant high gamma oscillations suggest that the developmental trajectory of motor function in children with migraine is impaired during migraine attacks and/or developmentally delayed. This finding indicates that childhood migraine may affect the development of brain function and result in long-term problems.     

Outcome of acute lower respiratory tract infection in infants: preliminary report of seven-year follow-up study.

Seven years after admission to hospital for acute lower respiratory tract infection in infancy 200 children and their matched controls were assessed for respiratory state and epidemiological characteristics. The index group comprised 100 cases where respiratory syncytial virus infection had been responsible for the index illness (group 1) and 100 cases in whom this organism had not been found (group 2). There were no differences between index and control groups in birth weight or gestational age but fewer index cases were breast fed. Social indices such as class distribution and family size were more favourable in controls, though housing standards and maternal smoking habits were similar in the two groups. The prevalence of subsequent respiratory symptoms--cough, wheeze, nasal discharge, and hearing difficulties--was greater in index cases as was absence from school and family doctor consultation for respiratory illness. Bronchitis and asthma were significantly more common in the index group. Impaired ventilatory function and bronchial hyperreactivity were found in index cases when compared with controls. No differences in clinical characteristics and outcome were found in the two groups of index cases. The question whether lung "damage" during lower respiratory tract infection predisposes to subsequent respiratory problems or whether certain infants are more vulnerable than others to respiratory illnesses (including lower respiratory tract infection) from the onset is unanswered.     

Infant and early childhood mortality in the Sine-Saloum region of Senegal

Infant and early childhood mortality in Senegal's Sine-Saloum region was investigated through use o f data from a 1982-83 family health survey. The survey involved interviews with 1894 married women 15-44 years of age living in extended family residential units in rural areas. Given evidence of substantial underreporting of early deaths, at least among children born before 1980, an adjustment factor was applied to the survey data. Infant mortality was estimated to be about 113/1000 live births and mortality before age 5 years was 263/1000. Strong mortality differentials, particularly after infancy, were noted according to the 2 socioeconomic variables included in the analysis: type of house and father's occupation. The probability of dying at ages 1-4 years was 50% higher among children living in traditional homes than among those in modern homes as well as among children whose fathers' were engaged in primary sector occupations (farming, livestock, fishing). Infant mortality showed no sex differential, while mortality at ages 1-4 years was 18% higher among females. Diarrheal and respiratory diseases were the 2 leading causes of death, killing at least 15% of all children by 5 years of age. Tetanus was an important cause of death during infancy, while measles and malaria were significant causes only after the 1st birthday. For all causes of death, the effect of socioeconomic status is higher in early childhood than in infancy, presumably because of the protective effect of breastfeeding. 82% of children who died had fever during their terminal illness, 51% had diarrhea, 39% had a cough, and 14% a rash. At least some mortality in this area might be prevented through treatment of these symptoms. However, calculating the degree to which particular interventions such as oral rehydration for diarrhea would reduce mortality is a complex task, requiring knowledge of replacement mortality, effectiveness of interventions, and the numbers of mothers who would utilize them.     

Childhood cancer in relation to indicators of magnetic fields from ground current sources

This study examines childhood cancer risk in relation to certain factors likely to indicate magnetic field exposure from ground currents in the home. Substantial ground currents are most often found in homes having conductive plumbing, in which an uninterrupted metallic path in the water pipes and water main connects the grounding systems of neighboring houses. Information on plumbing conductivity was obtained from water suppliers for the homes of 347 cases and 277 controls identified in an earlier study of magnetic field exposure and childhood cancer in the Denver area. An increased cancer risk was observed for children in homes with conductive plumbing: The matched odds ratio was 1.72 (1.03–2.88) and increased to 3.00 (1.33–6.76) when analysis was limited to cases and controls who were residentially stable from the reference date to the study date. A measurement metric likely to indicate active ground currents (measurements having above-median intensity and a nonvertical orientation of <55° from the horizontal) was identified. In contrast to measured field intensity alone, for which only modest associations with cancer have been reported, this metric shows a high and significant cancer risk [matched O.R. = 4.0 (1.6–10.0)] consistent over a range of intensity and angle cutpoints. Such elevated nonvertical fields were also associated with cancer in an independent data set, which was gathered to study adult nonlymphocytic leukemia in the Seattle area. The associations of cancer with conductive plumbing and with this exposure metric both suggest that cancer risk is increased among persons with elevated magnetic field exposure from residential ground currents. © 1995 Wiley-Liss, Inc.     

Visual screening of pre-school children.

In an attempt to reduce the incidence of persistent amblyopia and related disorders, routine screening of the visual function of pre-school children has been introduced in Ayrshire, the tests being carried out by orthoptists. A pilot study confirmed the feasibility of the screening. Under the definitive scheme, whose first three months'' results are presented, the children are examined as near as possible to their homes and the average attendance rate has been 86%. Thirty-seven of 442 children were referred to an ophthalmic clinic with suspected abnormalities (only one of which was not confirmed) that had not been picked up by the GP or welfare clinic. It is concluded that visual screening of pre-school children is administratively feasible and welcomed by parents, and that it can detect abnormalities missed by traditional procedures-which according to these results may be more than half of the total.     

Growth disorders in children with type 1 diabetes mellitus

The aim of the research was to analyze anthropometric variables in children with type 1 diabetes mellitus (DM) in relation with the stage of pubertal development at onset of disease and quality of metabolic control over five-year long observation. Diagnosed children were taller than their peers. This especially referred to age group between 4 and 9.5 years. On the whole, weight of the patients and healthy controls did not differ. However, the diagnosed children had substantially lower weight in puberty than healthy controls. Body mass index was significantly lower in the group of diagnosed children on the whole and in puberty. During a five-year long observation patients have had a significant retardation of growth. However, that retardation referred primarily to patients in prepuberty. Growth retardation was more pronounced with bad metabolic control. Growth was satisfactory if onset of disease had been in puberty. A significant weight gain was observed in patients in puberty whereas in those in prepuberty there was no significant change of body weight at the end of five-year long observation. Metabolic control did not affect observed changes. There were significant differences of anthropometric variables between those suffering from type 1 DM and their peers. The differences depended on the age at onset. The disease had a negative effect on growth with onset in prepuberty, whereas in puberty growth was satisfactory. However, puberty was a period in which patients increased their weight excessively. Prepuberty was a period in which growth had been significantly affected by metabolic control.     

Multivariate analysis of infant and child mortality in Java and Bali

The data used in this analysis come from the 1976 Indonesian Fertility Survey, part of the World Fertility Survey. The data are examined 3 times, fitting them to models which include different combinations of independent variables. The dependent variables are: 1) the proportion of children born between 5 and 15 years before the survey who died before their 1st birthday, for infant mortality; and 2) among those alive on their 1st birthday, the proportions who died before reaching their 5th birthday, for child mortality. The figures indicate that the chance of dying for children who were 1st born, born shortly after a previous child, whose previous sibling had died, who lived in rural areas, or had parents who were young and with little education, was greater than for children without these characteristics. In all 3 models used, the greatest net effects are attributed to the survival of a preceding sibling or the length of the preceding interval. Birth order does not have a significant gross effect on infant mortality, but the net effects are significant because of the control on maternal age. Education of both parents has significant effects, but these are overshadowed in magnitude by the demographic variables. Maternal education has a greater influence in determining differences in child mortality than was found for infant mortality. Father's education also has a significant independent effect, but mainly for 1st births. It is uncertain whether these variables are measuring the effect of schooling as such, or other characteristics such as economic status or various social roles adopted by people with different levels of education. The variables distinguishing urban from rural status shows significant gross effects which are greatly reduced when controls for other variables are introduced in the model which includes all births. That is to say, the difference in the survival chances of a child in the city is more a function of the education of its parents, and the associated demographic variables than city residence as such. Access to medical services is quite probably the main element in these differences. The findings are weakened to some extent by the lack of satisfactory data on household economic status which might have provided a better base for indirectly discerning the effects of nutrition and sanitation on mortality at young ages.     

Study of 8-year-old children with a history of respiratory syncytial virus bronchiolitis in infancy.

Thirty-five children known to have had respiratory syncytial virus bronchiolitis in infancy were examined at the age of 8 and their respiratory function tested. The results were compared with those in 35 controls matched for age, sex, and social class. Although 18 of the children who had had bronchiolitis in infancy had experienced subsequent episodes of wheezing, these were neither severe nor frequent in most cases and had apparently ceased by the age of 8. Nevertheless, the mean exercise bronchial lability of the children who had had bronchiolitis was significantly higher than that of the control children and the mean peak expiratory flow rate at rest significantly lower. Atopy, assessed by family and personal history alone, did not seem to be related to either bronchiolitis or wheezing episodes after bronchiolitis. The parents of the children who had had bronchiolitis smoked significantly more cigarettes during the infant''s first year of life than those of the control children. The results suggest that bronchiolitis and childhood asthma are not closely related. Bronchial hyperreactivity might be inherited independently of atopy, but environmental factors seem the most likely link between severe respiratory infection in infancy and chronic or recurrent respiratory illness in adult life.     

Road traffic and adverse effects on respiratory health in children.

OBJECTIVES--To examine whether road traffic in a big city has a direct effect on pulmonary function and respiratory symptoms in children. DESIGN--Cross sectional study. SETTING--Of all 7445 fourth grade children (aged 9-11 years) in Munich, 6537 were examined. Of the children with German nationality and the same residence during the past five years and known exposure data, 4678 questionnaires and 4320 pulmonary function tests could be analysed. MAIN OUTCOME MEASURES--Variables of pulmonary function by forced expiration and respiratory symptoms reported in a questionnaire; census data on car traffic collected in the school district. RESULTS--Density of car traffic ranged from 7000 to 125,000 cars per 24 hours. Multiple regression analysis of peak expiratory flow showed a significant decrease of 0.71% (95% confidence interval 1.08% to 0.33%) per increase of 25,000 cars daily passing through the school district on the main road. Maximum expiratory flow when 25% vital capacity had been expired was decreased by 0.68% (1.11% to 0.25%). In contrast, response to cold air challenge was not increased. The adjusted odds ratio for the cumulative prevalence of recurrent wheezing with the same exposure was 1.08 (1.01 to 1.16). Cumulative prevalence of recurrent dyspnoea was increased, with an odds ratio of 1.10 (1.00 to 1.20). Lifetime prevalence of asthma (odds ratio 1.04; 0.89 to 1.21) and recurrent bronchitis (1.05; 0.98 to 1.12) were not significantly increased. CONCLUSIONS--High rates of road traffic diminish forced expiratory flow and increase respiratory symptoms in children.     

Parents for children.

Parents for Children is a specialist adoption agency set up to find homes for children with special needs--that is, those with physical, mental, and emotional handicaps; older children; and sibling groups. Of the first 38 children placed, one child died and six placements broke down, although four children were later re-placed. Almost all the children referred to the agency had been in care for most of their lives. A full assessment of each child is necessary before placement, but in several cases the medical assessment in care had been inadequate. Many of the prospective parents themselves had serious medical conditions. The agency has proved that homes can be found for children in need, but there have been problems and parents require advice and support in the management of the children after placement.     

Long-term use of high-efficiency vacuum cleaners and residential airborne fungal-spore exposure

Exposure to fungal allergens is an important contributor to allergic respiratory disease, but information on the efficacy of residential fungal allergen-avoidance in allergic-disease management is lacking. Using vacuum cleaners with high-efficiency exhaust filtration is one method recommended for reducing residential allergen exposure levels, but their use to reduce fungal-spore exposure levels has not been evaluated. To evaluate the effectiveness of high-efficiency vacuuming to control airborne fungal-spore levels, fungal bioaerosols were repeatedly assessed over the course of 10 months in homes randomly assigned to groups using either conventionally filtered (control) or high-efficiency-filtered vacuum cleaners for routine vacuum cleaning. Air samples were analyzed for three fungal-spore categories representing taxa with predominantly outdoor sources and one representing taxa that commonly have indoor sources. In a two-way analysis of variance, sampling period had a significant effect on mean levels of all fungal-spore categories. Vacuum cleaner type had a marginally significant effect on the indoor spore category, with one high-efficiency vacuum group mean (of three) significantly lower than one control mean. No effect was observed of vacuum cleaner type on outdoor spore categories. Including home-environment variables in analysis of covariance models strengthened the effect of the vacuum-type treatment on the indoor spore category, with no effect on the three outdoor spore categories. Decreased indoor spore levels vs. controls were only observed in high-efficiency vacuum groups during the last sampling period, at the end of the heating season. The results suggest that using a vacuum with high-efficiency filtered exhaust could have some modest effectiveness in controlling airborne fungal-spore exposure in homes when infiltration of outdoor air is very limited.     

Echinacea purpurea L. in children: safety, tolerability, compliance, and clinical effectiveness in upper respiratory tract infections

Echinacea purpurea (L.) Moench was mistakenly taken from North America to Germany in 1939 where it was cultivated and various extractions were prepared and subsequently used to treat upper respiratory tract infections. Parents often administer Echinacea to their children, but safety data on the use of Echinacea in Canadian children is lacking. A screening history, physical examination, and daily record of symptoms from an initial visit through to a the follow-up visit 13 days later were used to increase patient safety. Each subject was administered an aerial part Echinacea extract. The dose was based on age (2.5 mL three times per day for children aged 2-5 years, and 5 mL two times per day for children aged 6-12 years) and administered for 10 days in an open-label trial. A rating scale was used to measure tolerance to the treatment. We assessed the safety and compliance of use of the Echinacea extract by measuring the amount of extract returned at the end of the study, having the parents complete and return a daily symptom diary, and recording the subjects' use of other natural health products or medications during the trial. Clinical effectiveness of the Echinacea extract could not be accurately assessed because of the small trial size and because the extract had been administered when some of the subjects had an upper respiratory tract infection that had begun 1 or more days prior to the study; however, each subject's symptoms improved. No allergic or adverse reaction occurred and no safety issues arose.     

乌司他丁对体外循环法洛四联症患儿围心脏手术期循环和呼吸功能的影响

目的:探讨乌司他丁对体外循环法洛四联症患儿围心脏手术期循环和呼吸功能的影响。方法:选取我院于收治的60例法洛四联症婴幼儿参与研究,并将其随机分为对照组和试验组两组,每组患儿30例。其中试验组患儿在体外循环前以及患儿进行手术后的三天内每天均给予10000U/kg乌司他丁,而对照组患儿则在相应的时间点给予等量的生理盐水。分析比较两组患儿的体外循环时间、心脏停搏时间、手术时间、在监护室治疗的时间以及患儿术后住院时间和患儿肺部感染发生例数等临床病理情况。结果:所有入选患儿均痊愈出院,在两组患儿的手术操作情况和治疗效果对比中,对照组患儿的手术时间、体外循环时间和心脏停搏时间均显著低于试验组患儿,但重症监护时间及术后住院时间则高于试验组患儿;在两组患儿治疗后的循环功能指标比较中,试验组患儿超滤后CVP和血管活性药物均低于对照组患儿而超滤后MAP则显著高于对照组患儿;在两组患儿治疗后的呼吸功能指标的比较中,试验组患儿的动脉血氧分压明显高于对照组患儿以及试验组患儿的术后机械通气时间和肺部感染例数均低于对照组患儿,两组患儿的数据比较差异除手术时间、体外循环时间和心脏停搏时间外均具有统计学意义(均P0.05)。结论:乌司他丁对体外循环法洛四联症患儿围心脏手术期的循环和呼吸功能具有较好的保护作用,值得在临床上加以广泛推广和运用。