Survey of allergic respiratory symptoms in grain terminal workers in the Port of Genoa

Summary Fifty workers from two grain elevator terminals were examined to evaluate the prevalence of respiratory symptoms and their relationship with grain dust exposure.Fifty per cent of subjects complained of respiratory symptoms (rhinitis, asthma, chronic cough and dyspnea on exertion). In 34% of the workers the ventilatory function revealed some abnormalities (slight or moderate obstruction).Twenty-two (44%) showed a positive cutaneous reaction to one or more of the allergens tested, mostly towardsDermatophagoides and storage mites. The self-measurement of PEF over 14 days in 27 workers, showed significant differences between symptomatic and asymptomatic subjects. In particular, the results obtained from the cutaneous reactions could suggest a bronchial hypereactivity, worsened by the working exposure to dusts. The monitoring of PEF appears to be a simple and useful method for investigating the relationship between respiratory symptoms and the working environment.     

沿海防护林防海煞危害初探

通过后牧村海岸防护林带附近空气中主要盐离子飘尘的观测分析表明,林带对大气盐尘的吸附和截留作用,无林带地区平均沉降量为４．３μｇ．ｍ＾－３．１００ｍ＾－１,通过林带时为１８．４μｍ＾－３．１００ｍ＾－１。林带的吸队量与树种、枝叶形状有关,侧柏对Ｃｌ＾－和Ｎａ＾＋的吸附量分别为６３３０和３３５０ｍｇ．ｋｇ＾－１,而黑松为１５７０和９５０ｍｇ．ｋｇ＾－１,空气中盐尘受天气条件特别是风速的影响,阴天,风速     

Sampling dust from human dwellings to estimate the prevalence ofDermatophagoides mite and cat allergens

Summary Quantification of specific allergens in household dust samples may provide important information for selecting appropriate allergen control methods, and monitoring efficacy and compliance. The purpose of this study was to investigate the source of variation in mite and cat allergen measurements associated with dust sample collection. Discrete and composite dust samples were collected on a filter using a special vacuum sampling device. Aqueous extracts of the dust samples were prepared thenDer p I,Der f I, andFel d I were quantitated by enzyme immunoassays (EIA). Mite and cat allergens were frequently detected in dust samples from human dwellings, and the amounts of these allergens varied significantly (p<0.01) among dwellings. The differences of allergen measurements among duplicate samples taken immediately and up to three weeks later appear to be much smaller than differences among houses and between rooms. Variation among dust samples taken from living rooms and bedrooms of the same dwelling suggest differences in allergen reservoirs. Composite samples formed by sampling specific objects within a room may provide a reliable estimate of allergen exposure in that room. Dust samples from discrete objects are useful to find and monitor specific reservoirs of mite and cat allergens.     

沙面结皮形成与微环境变化

研究结果表明沙坡头地区的大气年降尘(d相似文献   

Soil ingestion in children: Outdoor soil or indoor dust?

Soil ingestion estimates may play a prominent role in exposure estimation for risk assessments involving tightly bound soil contaminants such as dioxin, PCBs, and lead in soil. Since contamination is often localized to specific areas, the relative contribution of ingested soil due to outdoor soil and indoor dust may have a large impact on the risk assessment. This article examines data on 64 preschool children over 2 weeks to estimate the relative contribution of ingested soil from outdoor soil and indoor dust. Four principal methodological approaches are developed and presented to form the estimates, and their relative strengths and weaknesses are discussed.

The four approaches differ in their assumptions and their ability to detail differences in ingestion source. Two approaches (i.e., duration correlation method — approach 1 and group tracer ratio method — approach 2) were used that can only estimate the average ingestion source, where averages are calculated over subjects and weeks. Both of these approaches have sufficient limitations to preclude confidence in the resulting estimates.

The final two approaches (approach 3 — individual tracer ratio method and approach 4 — multiple statistical model method) were able to characterize ingestion source for individual subject‐weeks and offered more plausible estimates of soil ingestion. Greater emphasis is placed on approach 3 since it was biologically plausible and conceptually straightforward. Approach 3 indicated that 49.2% ± 29.2% of the residual fecal tracers were estimated to be of soil origin. These findings, which represent the first quantitative differentiation of soil vs. dust ingestion, have considerable application for a variety of environmental settings requiring exposure assessment.     

Lysis of mycelium ofFusarium oxysporum f. sp.udum in soil amended with organic matters

Summary Autoclaved or natural field soil amended with 0.1 to 5.0 per cent (W/W) of margosa cake, rice husk and sawdust with or without supplemental nitrogen were tested for lytic activity and bacterial numbers. Generally, non-amended autoclaved soil caused little or no lysis of mycelium ofF. oxysporum f. sp.udum; non-amended natural soil caused more lysis. Amendment of soil with margosa cake, rice husk or saw-dust with or without supplemental nitrogen greatly enhanced its lytic effect on the fungus. The degree of lysis depended on the dosage of amendment used and the stage of its decomposition in the soil. The extent of lysis increased as the bacterial population increased. Amongst bacteria,Bacillus subtilis was very common in most lytic zones.     

近20年来京津冀地区土壤风蚀扬尘颗粒物排放变化

京津冀地区是我国大气污染严重区域,土壤扬尘颗粒物排放变化研究对于改善京津冀地区空气质量具有重要意义。收集2000-2019年京津冀地区气候、土壤、植被覆盖数据,分析近20年来京津冀地区土壤扬尘颗粒物排放变化,揭示其变化的影响因素。结果显示2000-2019年京津冀地区土壤扬尘源总悬浮颗粒物（TSP）排放系数均值为1.79 t km^-2 a^-1,其中PM10占8.99%,PM2.5占0.25%。近20年土壤扬尘源TSP排放系数具有下降趋势,PM10和PM2.5排放系数变化过程与TSP一致。上述变化主要受气候因子变化影响,其次受植被覆盖度影响。分析发现近20年来京津冀地区土壤扬尘源TSP排放系数变化主要受年降水量影响。沧州市、天津市和石家庄市土壤扬尘源TSP、PM10和PM2.5排放系数均值较高,张家口市、保定市和沧州市土壤扬尘源TSP排放量占京津冀地区总量的19.18%、12.98%和11.63%。耕地土壤扬尘排放量最大占京津冀地区总量的59.83%,是抑制土壤扬尘源颗粒物排放的重点关注对象,其次为草地占15.66%。2019年邢台市土壤扬尘源PM10排放占观测值比例最高为12.66%,石家庄市和天津市占比也较高分别为11.09%和10.30%,沧州市和邯郸市占比分别为8.63%和8.02%。上述地区环境管理部门均应关注土壤扬尘源颗粒物排放对空气质量的影响。     

Effect of cotton dust on lungs among female workers in cotton industry in northern Gujarat,India

Byssinosis is a disabling occupational lung disease caused by cotton dust. It is a well-known occupational respiratory disease in cotton industry workers caused by cotton dust pollution. Many studies have been documented the effects of cotton dust on pulmonary function among workers employed in cotton-spinning mills. However, little data exist on the prevalence of this disorder in female workers particularly in western part of India. The present study was conducted to analyze the effects of exposure to cotton dust on pulmonary functions among female workers. The study was designed to assess the effects of exposure to cotton dust on lung functions among female cotton industry workers. Study group comprises 50 Female workers of cotton industry and control group comprises 50 age matched females who were neither worked in cotton industry nor exposed to cotton dust. Information was collected using standardized questionnaires, physical examination and spirometric measurements. Student''s T test was used to find the difference between spirometric parameters. All the respiratory parameters (FVC, FEV1, FEV1/FVC ratio, FEF 25-75 % PEFR and MVV) were reduced in cotton industry workers as compared with control subjects (p<0.0001) and no significant difference of SpO2 between groups. Cotton dust exposure makes huge impact on respiratory parameters of the cotton industry workers. This deterioration in respiratory health deteriorates with increasing duration of exposure. The health hazards caused by cotton dust should be controlled by creating awareness among the workers & employers.     

Pedoecological effects of a sand-fixing poplar (Populus simonii Carr.) forest in a desertified sandy land of Inner Mongolia, China

To assess the pedoecological effects of a 23-year old poplar ( Populus simonii Carr.) forest on soil amelioration and vegetation restoration via soil erosion reduction and atmospheric dust retention in a desertified sandy land ecosystem, daily dynamics of wind speed, sand transport and dust deposition rates were monitored over an erosive period from April through June in 2001, using fixed observation sites located at different positions within and around the forest. Soil and vegetation characteristics at these sites were also measured. The observation sites were placed at distances of 15H (as control), 6H and 3H (H is mean tree height) from the forest edge of the windward side (abbreviated CK, 6H-W and 3H-W respectively), forest center (FC), and at distances of 0H, 6H and 8H from the forest edge of the leeward side (FE-L, 6H-L and 8H-L respectively). Daily mean wind speed was significantly lower in different observation sites than CK, with FC having the greatest reduction of wind speed and 6H-W the least reduction. Daily transport rate of sand by wind was also significantly lower in different observation sites than CK, with FE-L having the greatest reduction of wind erosion and 6H-W the least reduction. The fact that the poplar forest will lose its functions against wind at a distance of about 12-fold tree height from the forest edge of the leeward side suggests that the effective wind-preventing range of the poplar forest is about 150 m. There was marked spatial and seasonal distribution of dust-fall rate. Over space, the rate of dust-fall was much greater within the forest than outside the forest. Over time, the daily dust deposition rate was greatest in April, followed in decreasing order by May, June, July, September and August, closely linked to the seasonal distribution pattern of dust storm. Significant positive changes in soil and vegetation parameters of the different observation sites during the 23 years that the poplar forest was established suggest the perceptible pedoecological effects of the poplar forest on soil development and restorative succession of plant community within its immediate vicinity through windbreak, soil erosion reduction and atmospheric dust retention. Understanding these pedoecological effects may aid in the design of protective forest systems in arid and semi-arid areas.     

矿物微尘对人体肠道菌群单一代表性菌株的体外作用研究

研究了矿物微尘对人体肠道菌群主要代表性菌株大肠埃希菌和嗜酸乳杆菌的体外作用。矿物微尘对大肠埃希菌生长起抑制作用,微尘浓度达3%时即对大肠埃希菌生长显著抑制,微尘浓度达20%时大肠埃希菌生长即受完全抑制,微尘浓度从3%到20%,大肠埃希菌虽受抑制但能生长,表明大肠埃希菌矿物微尘耐受能力较强。矿物微尘对嗜酸乳杆菌生长影响复杂,低浓度时起促进作用,较高浓度时起抑制作用,微尘浓度达5%时嗜酸乳杆菌生长即受完全抑制,嗜酸乳杆菌矿物微尘耐受能力较弱,远小于大肠埃希菌。确立矿物微尘对人体肠道代表性细菌的抑制浓度及致死浓度为环保监测和城市空气质量监控提供了科学依据。