A comparative study of hematological parameters of α and β thalassemias in a high prevalence zone: Saudi Arabia

BACKGROUND AND AIMS:

Saudi Arabia falls in the high prevalent zone of αα and β thalassemias. Early screening for the type of thalassemia is essential for further investigations and management. The study was carried out to differentiate the type of thalassemia based on red cell indices and other hematological parameters.

MATERIALS AND METHODS:

The study was carried out on 991 clinically suspected cases of thalassemias in Riyadh, Saudi Arabia. The hematological parameters were studied on Coulter STKS. Cellulose acetate hemoglobin electrophoresis and high-performance liquid chromatography (HPLC) were performed on all the blood samples. Gene deletion studies were carried out by restriction fragment length polymorphism (RFLP) technique using the restriction endonucleases Bam HI.

STATISTICAL ANALYSIS:

Statistical analysis was performed on SPSS 11.5 version.

RESULTS:

The hemoglobin electrophoresis and gene studies revealed that there were 406 (40.96%) and 59 (5.95 %) cases of β thalassemia trait and β thalassemia major respectively including adults and children. 426 cases of various deletion forms of α thalassemias were seen. Microcytosis was a common feature in β thalassemias trait and (-α/-α) and (--/αα) types of α thalassemias. MCH was a more significant distinguishing feature among thalassemias. β thalassemia major and α thalassemia (-α/αα) had almost normal hematological parameters.

CONCLUSION:

MCV and RBC counts are not statistically significant features for discriminating between α and β thalassemias. There is need for development of a discrimination index to differentiate between α and β thalassemias traits on the lines of discriminatory Indices available for distinguishing β thalassemias trait from iron deficiency anemia.     

Biological yields through agricultural extension activities and services: A case study from Al-Baha region – Kingdom of Saudi Arabia

PurposeThis research determines the extent to which farmers benefit from agricultural extension activities and services through realizing higher biological crop yields in the Al-Baha region of the Kingdom of Saudi Arabia. Additionally, the nature of the relationship between the personal, economic and social characteristics of farmers and the degree to which they benefit from agricultural extension activities and services are studied.MethodologyA simple random sample representing the community of 315 farmers was drawn. Data were collected through a personal interview with a pre-tested questionnaire to satisfy the objectives of the study. Data are subjected to analyses and are interpreted in terms of percentages, arithmetic averages, and standard deviations in addition to the simple Pearson correlation coefficients.ResultsThe results show that most of the respondents depend on personal experience, friends, family and neighbors, merchants and sellers of agricultural production supplies as sources of agricultural information for enhanced crop yields. Multiple regression analysis reveals that both the educational status and the agricultural information sources are important factors that increase farmers benefit from extension activities. Farmers receive most benefits from the extension activities and services from bringing in foreign workers, conducting field trips to farms, and identifying problems faced by farmers.Research limitations/implicationsThe outcome of this questionnaire limits generalization of the findings for other parts of the Kingdom due to geographical and natural resources variations.Practical implicationsThe personal and socio-economic characteristics of the surveyed population provide the extension service with insight into their composition – a basis to formulate workable extension programs. For the extension planners of the area, this effort provides a baseline study and may assist with targeting the appropriate farmers and catering the right solutions to the problems. Such a study will help devise meaningful extension programs and save time and resources.Originality/valueLittle previous research on the usefulness of the Extension Service has been conducted in the region.ConclusionsEffective, well-planned extension programs targeting the educated and mature farmers provided more benefits and helped them obtain higher crop yields.     

Dissolved nitrogen in drinking water resources in Al-Mahareth village of Assir – Saudi Arabia

A water quality study was carried out on ground water wells, which serve as drinking water sources in farming communities in Al-Mahareth village of Assir region of the Kingdom of Saudi Arabia. The objective of this research was to determine concentrations of different forms of nitrogen in drinking water samples. Water samples were collected from these sources every 3 months (from January to December 2008) and analyzed for ammonia, nitrate and nitrite using the Plaintest Photometer Method. Results indicated that the annual mean concentration of nitrate, nitrite and ammonia varied from 23.09 to 25.06 mg/l, 0.006 to 0.36 mg/l and 0.008 to 0.179 mg/l, respectively. An important observation was that, in general, higher nitrate and nitrite concentrations were found during the rainy season compared to the dry season. Concentrations of these potentially toxic substances were below WHO acceptable limits for surface and ground waters, indicating that these water resources appear safe for drinking from a dissolved nitrogen perspective.     

Molecular markers in management of ex situ PGR – A case study

Worldwide germplasm collections contain about 7.4 million accessions of plant genetic resources for food and agriculture. One of the 10 largest ex situ genebanks of our globe is located at the Leibniz Institute of Plant Genetics and Crop Plant Research in Gatersleben, Germany. Molecular tools have been used for various gene bank management practices including characterization and utilization of the germplasm. The results on genetic integrity of long-term-stored gene bank accessions of wheat (self-pollinating) and rye (open-pollinating) cereal crops revealed a high degree of identity for wheat. In contrast, the out-pollinating accessions of rye exhibited shifts in allele frequencies. The genetic diversity of wheat and barley germplasm collected at intervals of 40 to 50?years in comparable geographical regions showed qualitative rather than a quantitative change in diversity. The inter- and intraspecific variation of seed longevity was analysed and differences were detected. Genetic studies in barley, wheat and oilseed rape revealed numerous QTL, indicating the complex and quantitative nature of seed longevity. Some of the loci identified were in genomic regions that co-localize with genes determining agronomic traits such as spike architecture or biotic and abiotic stress response. Finally, a genome-wide association mapping analysis of a core collection of wheat for flowering time was performed using diversity array technology (DArT) markers. Maker trait associations were detected in genomic regions where major genes or QTL have been described earlier. In addition, new loci were also detected, providing opportunities to monitor genetic variation for crop improvement.     

Evaluation of cytokines,oxidative stress markers and brain-derived neurotrophic factor in patients with fibromyalgia – A controlled cross-sectional study

ObjectivesPrevious studies measuring serum levels of biomarkers of inflammation/oxidative stress and neurotrophins levels in fibromyalgia (FM) have rendered inconsistent results. In the present study, our aim was to explore the levels of interleukins, oxidative stress markers and brain-derived neurotrophic factor (BDNF) in patients with FM in relation to depression and severity of disease.MethodsIn a prospective controlled cross-sectional study, serum concentrations of IL-6, IL-8, IL-10, TNF-α, thiobarbituric acid reactive substances (TBARS), protein carbonyl and BDNF were measured in 69 FM patients and 61 healthy controls (all women). In the FM group, the Fibromyalgia Impact Questionnaire (FIQ), the Beck Depression Inventory (BDI) and the Hamilton Depression Rating Scale (HDRS) were applied. Mann Whitney’s and Spearman correlation tests were used for statistical analysis.ResultsThe FM patients demonstrated a significant impact of the disease on quality of life (FIQ 70.2 ± 17.8) and most of them had depression at some level (82.6% and 87.0% as assessed by BDI and HDRS, respectively). Most biomarkers (IL-6, IL-8, TNF-α, TBARS and protein carbonyl) and BDNF did not differ significantly between patients and controls, but the IL-10 levels were higher in FM patients (adjusted p = 0.041). Among FM patients, there was no correlation of HDRS, FIQ, and BDI scores with any biomarker tested here.ConclusionWe observed no significant differences in biomarkers between FM patients and controls, except for higher levels of IL-10 (an anti-inflammatory cytokine) in patients. The levels of biomarkers were not correlated with parameters of disease and depression severity.     

Food waste posing a serious threat to sustainability in the Kingdom of Saudi Arabia – A systematic review

Worldwide, food waste is one of the prime issues threatening food security and the Kingdom of Saudi Arabia (KSA) is not an exception. With 427 kg of food wasted per capita per year, the country ranks among the top food wasters. Ironically, the Kingdom has limited arable lands and scarce water resources to support mass-scale agriculture and to feed its increasing population, KSA relies heavily on imports and subsidized food to meet needs. Yet, food is wasted at restaurants, caterers, cafeterias and, especially, by households such that food waste is the single-largest component of the landfills. The review article is based on the grey and scientific literature published in the English and Arabic languages on the issue of food waste in Saudi Arabia. Information sources like Web of knowledge, online resources and the databases available through the King Saud University, Saudi Arabia were accessed and used to collect information on food waste, its social, cultural, economic and environmental impacts and related topics. Since food items and groceries are abundantly available to all living in KSA and they are highly subsidized, the residents take food for granted. According to a recent survey, about 78% of food purchased in KSA is discarded each week in order to make room for new groceries. The factors responsible for food waste include: lack of awareness; and insufficient and inappropriate planning when shopping. Food waste in restaurants, celebrations, social events and occasions are enormous. Waste is common in festivals and special events where the customs is to provide more food than required. There is a need to change society’s food culture, particularly among the women and the youth, as they are largest segment of the society and the prime food wasters. The analysis of the factors responsible for food waste, identified in this article suggests a “Stop Wasting Food” campaign should be launched. It is also recommended to determine and activate the role of extension education to reduce food waste in the KSA through vibrant capacity building programs for youth and women, in particular, and society in general.     

Socio-economic factors affecting the conservation of natural woodlands in Central Riyadh Area – Saudi Arabia

This study aimed to identify some socioeconomic factors affecting local people in central Riyadh area for the utilization of wood and other energy sources in cooking and heating in order to develop some recommendations for conserving woodlands. The study results revealed that gas is the most common energy source used for cooking with a mean usage level of 2.79 (SD = 0.58). On the other hand, wood ranked first for heating with the highest mean, usage level of 1.90 (SD = 1.06). However, electricity and gas as sources of energy for heating ranked second and third with mean usage level of 1.81 and 0.80 respectively. The study revealed that local people with the university education were significantly making higher use of electricity for both cooking and heating and those with no formal education ranked the highest on wood use for both cooking and heating. In addition, those living in traditional houses significantly used more wood for cooking than those living in villas and apartments. Also, local people with high income levels significantly were using more electricity for heating than others. The study recommended conducting extension and environmental awareness raising programs to enhance local residents’ adoption of wood substitutes, promoting employment opportunities for unemployed locals, and subsidizing prices of alternative energy sources.     

Pattern and risk factors of sharp object injuries among health care workers in two tertiary hospitals,Al Taif-Kingdom of Saudi Arabia 2016–2018

Occupational exposure of healthcare workers to blood and body fluids following skin injury constitutes a risk for transmission of blood-borne pathogens. The risk of exposure is greater as well. The present study aimed to determine the burden and risk factors of sharp object injuries in two tertiary hospitals in the Taif City KSA. Retrospective review of needle stick injury records was included from the two hospital's staff clinics. A Total of 131 health professionals (employees) recorded as exposed to sharp object injuries from both hospitals were enrolled during period 2016–2018. The collected data was cleaned, reviewed and analyzed using Statistical Package of Social Sciences SPSS ver. 25. The result of the study revealed that, the mean age for the 131 enrolled participants was 31 ± 6.6, Male to Female Ratio was 1:3. The most affected age group was 20–30 years (55.7%). Females were more affected 98 out of 131 (74.8%) than male (33out of 131 (25.2%). And there is increasing incidence rates of exposure from 2.89 /10.000 patient/day in 2016 to 3.42/ 10.000 patients'/day in 2017, with highest exposed nationalities; Filipino 42 (32.1%), Saudi 31 (23.7%), and Indians 26 (19.8%), the remaining 24.5% were from 10 mixed nationalities. The frequent affected divisions were: ER, surgical ward, operation room, ICU, laboratory, Medical W, Medical waste facilities (19.8%, 15%, 12.2%, 9.2%, 92% respectively). The most affected HCWs categories were nurses 74(56.5%), doctor 23(17.6%) and housekeeping 18 (13.7%). And the needle prick 104(79.4%) and cut wound 15(11.5%) constitute the highest type of injuries and were during operation 23 (17.6%), waste collection 15 (11.5%), cannulation 12 (9.2%) and giving injection 12 (9.2%). The common devices caused injuries were bore hole needle 63(48.1%), suture needle **(13.7%), cannula and insulin syringe 13 (9.9%) each. This study concluded that, as from 2016−2018, there was an increasing rate of reported accidental exposure to sharp needle injuries amongst HCWs from 3.0 to 3.4/10.000 patient/day, and the younger and nurses were mostly impacted. Workplace, distress, work types and load had influences on injuries rates and types. Fortunately, no exposure among employee with HBV, HCV and HIV seroconversion were documented.     

Energy expenditure and water flux of Rüppell's foxes in Saudi Arabia

Scattered populations of Rüppell's foxes (Vulpes rueppelli) occur across the deserts of northern Africa and Arabia. Little is known about the biology of these canids, especially the physiological mechanisms that contribute to their ability to live in such harsh environments. For individuals from Saudi Arabia, we tested the hypotheses that Rüppell's foxes have a reduced basal metabolic rate and total evaporative water loss (TEWL), parameters measured in the laboratory, and a reduced field metabolic rate (FMR) and water flux when free-living. Under basal conditions in the laboratory, males, which averaged 1,858 g in body mass, had an oxygen consumption of 914.9 mL O(2)/h, whereas females, which weighed on average 1,233 g, consumed 682.9 mL O(2)/h; rates of oxygen consumption translated to 441.4 kJ/d and 329.4 kJ/d, respectively. TEWL averaged 52.6 g H(2)O/d for males and 47.5 g H(2)O/d for females. We found no evidence that basal metabolism is reduced in Rüppell's foxes, but their TEWL was remarkably low: 50.9% of allometric prediction for males and 64.5% for females. In the wild during winter, males expended energy at a rate of 1,306.5 kJ/d, whereas females had an expenditure of 722.8 kJ/d. Analysis of covariance with FMR as the dependent variable, sex as a fixed factor, and body mass as a covariate showed no statistical difference in FMR between sexes. Water flux did not differ significantly between sexes and averaged 123 mL H(2)O/d, a value 30% lower than the kit fox from the deserts of southwestern North America. FMR was positively related to nocturnal activity levels as FMR (kJ/d) = -2,900.1+55.5 (% of time moving). The water content of prey items varied between 1.9 and 4.1 g H(2)O/g dry matter consumed. Based on these values and knowledge of their diet, we calculated that foxes captured about one rodent and a variety of anthropods per night of foraging.     

Effects on the prostate of environmental cadmium exposure – A cross-sectional population study in China

To explore possible effects of environmental cadmium exposure on prostate in humans, and the possible relationship of serum sex hormones to occurrence of clinic signs of tissue changes in the prostate, a case-control study was undertaken in the southeast part of China in 1998. A total of 297 male volunteers from a control area and two cadmium-polluted areas were included as subjects in this study. All the subjects were required to answer a questionnaire and to undergo a complete physical examination including digital-rectal examination (DRE). Blood and urine samples were collected. Serum total prostate specific antigen (PSA), total serum testosterone (T), follicle stimulating hormone (FSH) and luteinizing hormone (LH) were measured by radioimmunoassay and enzymeimmunoassay method, respectively. The data of urinary cadmium (U-Cd) and blood cadmium (B-Cd) were obtained by atomic absorption spectrometry (AAS) as an indicator of cadmium body burden. Statistical analysis was applied to investigate a possible relation between cadmium exposure and prostate pathological changes. The results show that there is a clear dose-response relationship between cadmium exposure and the prevalence of cases with abnormal PSA. The blood cadmium content in cases with positive DRE was significantly higher than that of subjects with negative DRE (P<0.05). Significant differences in the level of FSH between cases with positive DRE and the normal subjects were also noted (P<0.05). These results indicate that chronic environmental cadmium exposure is associated with injuries to human prostate. A possible relationship to changes in circulating sex hormones needs further investigation.     

Bioelements in the treatment of burn injuries – The complex review of metabolism and supplementation (copper,selenium, zinc,iron, manganese,chromium and magnesium)

Appropriate nutrition is a key component of burn treatment and should be regarded as an integral part of the therapeutic process in burn patients. A nutritional intervention plan should not only allow for adequate quantities of energy and protein but also carefully consider the supply of macro- and micronutrients. As a result of the severe inflammatory response, oxidative stress, and hypermetabolic state, accompanied by often extensive exudation in burn patients, there is a considerable loss of macro- and micronutrients, including essential trace elements. This leads to certain complications, involving e.g. more frequent infections and impaired wound healing. Our current body of knowledge is still insufficient, and the studies carried out to date focus for the most part on the imbalances in trace elements, such as copper (Cu), selenium (Se), and zinc (Zn). Nevertheless, there are many other trace elements involved in immune functions, regulating gene expression or antioxidant defense, and many of those have not been properly investigated in a clinical setting. Due to the insufficient amount of unambiguous literature data and relatively few, often dated, studies carried out with small patient groups, further evaluation of macro- and microelements in burn patients seems indispensable, e.g. to bring up to date local nutritional protocols.     

A preliminary study on the insect fauna of Al-Baha Province,Saudi Arabia,with descriptions?of?two?new?species

A preliminary study was carried out on the insect fauna of Al-Baha Province, south-western part of Saudi Arabia. A total number of 582 species and subspecies (few identified only to the genus level) belonging to 129 families and representing 17 orders were recorded. Two of these species are described as new, namely: Monomorium sarawatensis Sharaf & Aldawood, sp. n. [Formicidae, Hymenoptera] and Anthrax alruqibi El-Hawagry sp. n. [Bombyliidae, Diptera]. Another eight species are recorded for the first time in Saudi Arabia, namely: Xiphoceriana arabica (Uvarov, 1922) [Pamphagidae, Orthoptera], Pyrgomorpha conica (Olivier, 1791) [Pyrgomorphidae, Orthoptera], Catopsilia florella (Fabricius, 1775) [Pieridae, Lepidoptera], Anthrax chionanthrax (Bezzi, 1926) [Bombyliidae, Diptera], Spogostylum near tripunctatum Pallas in Wiedemann, 1818 [Bombyliidae, Diptera], Cononedys dichromatopa (Bezzi, 1925) [Bombyliidae, Diptera], Mydas sp. [Mydidae, Diptera], and Hippobosca equina Linnaeus, 1758 [Hippoboscidae, Diptera]. Al-Baha Province is divided by huge and steep Rocky Mountains into two main sectors, a lowland coastal plain at the west, known as “Tihama”, and a mountainous area with an elevation of 1500 to 2450 m above sea level at the east, known as “Al-Sarat or Al-Sarah” which form a part of Al-Sarawat Mountains range. Insect species richness in the two sectors (Tihama and Al-Sarah) was compared, and the results showed that each of the two sectors of Al-Baha Province has a unique insect community. The study generally concluded that the insect faunal composition in Al-Baha Province has an Afrotropical flavor, with the Afrotropical elements predominant, and a closer affiliation to the Afrotropical region than to the Palearctic region or the Eremic zone. Consequently, we tend to agree with those biogeographers who consider that parts of the Arabian Peninsula, including Al-Baha Province, should be included in the Afrotropical region rather than in the Palaearctic region or the Eremic zone.     

Clinical and epidemiological aspects of human parvovirus B19 infection in an urban area in Brazil (Niterói city area,State of Rio de Janeiro,Brazil)

This study was designed to analyse the clinical and epidemiological data from human parvovirus B19 cases in a six-year study of rash diseases conduct in an urban area in Brazil (Niterói city area, State of Rio de Janeiro). A total of 673 patients with acute rash diseases were seen at two primary health care units and at a general hospital. A clotted blood sample was collected from all subjects at the time of consultation. Forty-nine per cent (330 cases) of the patients were negative for dengue, rubella and measles IgM or for low avidity IgG to HHV-6. Of these 330, 105 (31.8%) were identified as IgM positive to parvovirus B19 by using an antibody capture EIA. During the study period, three distinct peaks of parvovirus infection were detected, suggesting that the disease appears to cycle in approximately 4-5 years. B19 infection was characterized by variable combinations of fever, flu-like symptoms, arthropathy, and gastrointestinal symptoms. Frequency of fever and arthropathy was substantially higher in adults, 75% [chi2 (1 D.F.) = 11.39, p = 0.0007] and 62.5% [chi2 (1 D.F.) = 29.89, p = 0.0000], respectively. "Slapped-cheek" appearance and reticular or lace-like rash were seen in only 30.1% of the children. No adult presented this typical rash. The lack of the typical rash pattern in a large proportion of parvovirus B19 and the similarity of clinical manifestations to other rash diseases, specially to rubella, highlight the difficulty of diagnosing B19 infection on clinical grounds alone.     

Gastric cancer & prospects of cancer in Saudi Arabia peninsula

Gastric cancer is classified to be an aggressive disease with poor treatment outcome, as most cases remain undetected until later stages, wherein surgery and few chemotherapeutics become the only recommended treatment course. The process of cancer development is multistep involving many stages and types of precancerous lesions, and hence, routine monitoring becomes a necessity in those detected with these or exposed to risk factors. Studying the pattern of gastric cancer for any geographical region is also important to control mortality and focus on implementation of efficient management and treatment guidelines. The cause for gastric cancer can be genetic, racial as well as environmental, and hence the pattern of this malignancy differs across geographical regions and between the developing and the developed nations. In case of the Kindgom of Saudi Arabia, very few hospital-based reports have been published highlighting the pattern of gastric cancer, and the associated incidence and mortality rates. However, classified to be one of the most crucial cancer forms in Saudi Arabia, research pertaining to epidemiology, presentation and pathological features are limited. Studying gastric cancer occurrence from public health viewpoint is important also because eradication of causative agents like those that H. pylori has also shown been not reduce the risk of cancer development among individuals with atrophic metaplastic gastritis. In case of Saudi Arabia, many inherent risks for this malignancy exists like waterpipe smoking and shift in diet pattern from the traditional Mediterranean diet. Our review focusses on pattern of gastric cancer on a global scale in comparison to scenario in Saudi Arabia. The aim is to encompass all of the less stressed upon facts about this malignancy in the Kingdom, paving way for future work in this regards.     

Association between self-care management practices and glycemic control of patients with type 2 diabetes mellitus in Saud Arabia: A cross –sectional study

ObjectiveIn this cross-sectional study, we aimed to determine the association of self-care management practices and glycemic control of type 2 diabetes mellitus in Saudi Arabia.MethodsA total of 352 type 2 diabetes mellitus (T2DM) patients from two public tertiary hospitals in Saudi Arabia participated in this study. All T2DM patients were recruited and interviewed by a researcher between January to April 2018 from the outpatient diabetes clinics. All respondents answered a four-part questionnaire which includes demographics data, Diabetes Self-Management Questionnaire (DSMQ). Linear Regression was performed to assess the significance of predictors and compute the coefficient of determination.ResultsThe mean age of the participants was 51.89 ± 10.94. Of the 352 participants, 52% were obese (BMI: ≥30 kgm²) and 77% of the participants had glycated haemoglobin (HbA1c) over 7%. The analysis showed that subscale of Glucose management was the strongest predictor of Hba1c levels of participants’ followed by physical activity. Gender and marital status emerged as significant predictors for their self-care management practices. Female patients had more self-care management practices than male patients (B 0.20; 95CI 0.10– 0.96 (p = 0.015).ConclusionThis study provides an evidence on the self-care management of T2DM patients in Saudi Arabia. The high self-care management found in the study highlights that the patients are aware of the severity of and possible complications associated with T2DM.     

Incidence of and Risk Factors Associated with Pulmonary and Extra-Pulmonary Tuberculosis in Saudi Arabia (2010–2011)

Setting

National Tuberculosis Program, Department of Public Health, Ministry of Health, Kingdom of Saudi Arabia (KSA).

Objective

To summarize data on the incidence of tuberculosis and associated risk factors for cases reported during 2010–2011.

Design

Retrospective analysis of routinely collected data through an established national disease notification system of the Ministry of Health in KSA.

Results

The estimated incidence of all forms of tuberculosis fell from 15.8/100000 (95% CI: 15.3/100,000–16.3/100,000) in 2010 to 13.8/100,000 (95% CI: 13.4/100,000–14.2/100,000) in 2011. Saudis experienced a decrease from 11.8/100,000 (95% CI: 11.3/100,000 to 12.3/100,000) in 2010 to 9.9/100,000 (95% CI: 9.5/100,000–10.4/100,000) in 2011 while the incidence in non-Saudis declined from 24.7/100,000 (95% CI: 23.6/100,000 to 25.7/100,000) in 2010 to 22.5/100,000 (95% CI: 21.5/100,000 to 23.4/100,000) in 2011. The proportion of Extra Pulmonary TB (EPTB) which increased minimally from 30% in 2010 to 32% in 2011 was higher than global figures and strongly associated with age, sex, nationality and occupation.

Conclusion

The current estimated incidence of about 14/100,000 in 2011 is less than half its estimated value of 44/100000 in 1990. Without prejudice to any under-reporting, the KSA appeared to be on the course for TB elimination by 2050 having reached the first milestone set by WHO. The proportion of EPTB remains higher than global figure and age, sex, nationality and occupation were significant independent predictors of EPTB.     

Assessment of airborne endotoxin in sandstorm dust and indoor environments using a novel passive sampling device in Al Zulfi city,Saudi Arabia – Establishing threshold exposure levels

The impact of sandstorm dust events affects local air quality and public health. These issues are becoming of greater concern in Saudi Arabia. There is a significant lack of research on airborne endotoxin exposure and analysis in the Middle East countries and no coherent body of research exists focusing on sandstorm dust in worldwide. In this study, we used a novel design of an aluminum foil plate (AFP) electrostatic dust cloth (EDC) for the passive air sampling of sandstorm dust. A total of 38 sandstorm dust samples were collected during sandstorm episodes occurring between January and April 2020 in both indoor (7 days, n = 20) and outdoor environments (24 h, n = 18). After exposure, and following an extraction procedure, bacterial endotoxin levels were measured using the Limulus Amoebocyte Lysate (LAL) gel clot method. The study highlights that the airborne endotoxin level observed was between 10 and 200 EU/m² in both indoor and outdoor environments, during a sandstorm event. Agricultural activities and farmhouses observed higher airborne endotoxin levels. In general, increased endotoxin levels were related to the severity of the sandstorms. Given that the observed values were high as per existing guidelines for respiratory health, we recommend the setting an occupational airborne exposure limit for bacterial endotoxin. This is the first report and further studies across various sandstorm-hit regions will need to be undertaken, together with various sampling methods, in order to assess for seasonal and geographic trends.     

Dynamics of soil carbon,nitrogen, and phosphorus in calcareous soils after land-use abandonment – A chronosequence study

Aims

The objective of this study was to investigate changes in soil total organic C (TOC), total nitrogen (TN), phosphorus (P) fractions, and microbial community structure during secondary succession after abandonment of vineyards on calcareous soils.

Methods

Two chronosequences covering 200 years and differing in aspect and slope were established in Hungary, and the upper 10 cm of the mineral soils were studied.

Results

We found strong increases in TOC concentrations after land-use abandonment, especially at the south-exposed sites. The TOC/TN ratio increased by a factor of 1.3 in the south-west exposed chronosequence and by a factor of 1.6 in south exposed chronosequence. The concentration of labile P (NaHCO₃-extractable P) diminished during the first 50 years after land-use abandonment, leading to low P availability at the later stages of the succession. The total organic P (TOP) concentration increased during the first 40 years after abandonment. At the later stages of succession, TOP concentrations decreased again, while the ratio of TOC/TOP increased continuously over 200 years. The ratio of arbuscular-mycorrhizal-fungi-to-bacteria (AMF/bacteria) increased strongly during the first decade after abandonment of the vineyards.

Conclusions

Our study indicates that impacts of former cultivation on secondary ecosystems persisted for more than a century, and that especially P concentrations showed long lasting legacy effects.