Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “IRRIGATION”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 487 records · Page 27Linked to original sources
PubMed2002

Effect of irrigation method on transmission to and persistence of Escherichia coli O157:H7 on lettuce.

In this study, the transmission of Escherichia coli O157:H7 to lettuce plants through spray and surface irrigation was demonstrated. For all treatments combined, the number of plants testing positive following a single exposure to E. coli O157: H7 through spray irrigation (29 of 32 plants) was larger than the number testing positive following surface irrigation (6 of 32 plants). E. coli O157:H7 persisted on 9 of 11 plants for 20 days following spray irrigation with contaminated water. Immersion of harvested lettuce heads for 1 min in a 200 ppm chlorine solution did not eliminate all E. coli O157:H7 cells. The results of this study suggest that regardless of the irrigation method used, crops can become contaminated; therefore, the irrigation of food crops with water of unknown microbial quality should be avoided.

Agriculture↗
PubMed2004

A rapid and automated fiber optic-based biosensor assay for the detection of Salmonella in spent irrigation water used in the sprouting of sprout seeds.

Recent outbreaks of foodborne illness have been linked to the consumption of contaminated sprouts. The spent irrigation water used to irrigate sprouts can carry many microorganisms, including pathogenic strains of Escherichia coli and Salmonella enterica. These pathogens are believed to originate from the seeds. The U.S. Food and Drug Administration recommends that sprout producers conduct microbiological testing of spent irrigation water from each production lot at least 48 h after seeds have germinated. Microbial analysis for the detection of Salmonella is labor-intensive and takes days to complete. A rapid and automated fiber-optic biosensor assay for the detection of Salmonella in sprout rinse water was developed in this study. Alfalfa seeds contaminated with various concentrations of Salmonella Typhimurium were sprouted. The spent irrigation water was assayed 67 h after alfalfa seed germination with the RAPTOR (Research International, Monroe, Wash.), an automated fiber optic-based detector. Salmonella Typhimurium could be positively identified in spent irrigation water when seeds were contaminated with 50 CFU/g. Viable Salmonella Typhimurium cells were also recovered from the waveguides after the assay. This biosensor assay system has the potential to be directly connected to water lines within the sprout-processing facility and to operate automatically, requiring manual labor only for preventative maintenance. Therefore, the presence of Salmonella Typhimurium in spent irrigation water could be continuously and rapidly detected 3 to 5 days before the completion of the sprouting process.

Biosensing Techniques↗
PubMed2004

Irrigation water as source of foodborne pathogens on fruit and vegetables.

Awareness is growing that fresh or minimally processed fruit and vegetables can be sources of disease-causing bacteria, viruses, protozoa, and helminths. Irrigation with poor-quality water is one way that fruit and vegetables can become contaminated with foodborne pathogens. Groundwater, surface water, and human wastewater are commonly used for irrigation. The risk of disease transmission from pathogenic microorganisms present in irrigation water is influenced by the level of contamination; the persistence of pathogens in water, in soil, and on crops; and the route of exposure. Groundwater is generally of good microbial quality, unless it is contaminated with surface runoff; human wastewater is usually of very poor microbial quality and requires extensive treatment before it can be used safely to irrigate crops; surface water is of variable microbial quality. Bacteria and protozoa tend to show the poorest survival outside a human host, whereas viruses and helminths can remain infective for months to years. Guidelines governing irrigation water quality and strategies to reduce the risk of disease transmission by foodborne pathogens in irrigation are discussed.

Consumer Product Safety↗
PubMed2005

Microbial assessment of irrigation water used for production of fruit and vegetables in Ontario, Canada.

Five hundred one irrigation water samples were collected from 27 irrigation water sources on 17 farms in southern Ontario, Canada, over a single irrigation season in 2002. The water samples were tested for the presence of the following bacterial water quality indicators: total coliform bacteria, fecal coliforms, Escherichia coli, and fecal streptococci. The median values per 100 ml of these indicators in the irrigation water samples were 3,000, 33, 15, and 1, respectively. Between 70.6 and 98.2% of irrigation water samples contained acceptable levels of fecal coliforms or E. coli, according to published irrigation water quality guidelines. Significant correlations (P < 0.05) were observed between the concentrations of different bacterial indicators and the degree of recent precipitation and concentrations of total coliforms and fecal streptococci. With the exception of fecal streptococci, which increased in number toward the end of the study, none of the indicators displayed a significant trend over the course of the season, as determined by linear regression analysis of indicator concentrations over time (P > 0.05).

Agriculture↗
PubMed2001

Reuse of reclaimed wastewater for golf course irrigation in Tunisia.

In Tunisia, golf courses are irrigated with secondary treated effluent stored in landscape impoundments. The impact of the conveyance and storage steps on the physical-chemical and biological quality of irrigation water was evaluated on three golf courses over two years. It was found that the water quality varies all along the water route, from the wastewater treatment plant up to the irrigation site: nutrient and bacteria contents decreased along the route in the three cases. This variation depends on the wastewater quality, the length of the pipes conveying water, the number of regulation reservoirs and ponds, the water residence time in pipes, reservoirs and ponds, and the operation of the ponds. The bacteriological quality of irrigation water deteriorates during the irrigation period in the three golf courses as the ponds are operated as continuous flow reactors. The results obtained in this study indicate the inability of golf water supplies, as currently managed, to properly sanitize reclaimed wastewater and meet target quality criteria recommended by WHO (1989) for water intended for recreational use. For a safe reuse of reclaimed wastewater for golf course irrigation, changes in the design and operation of the ponds should be planned or additional treatment steps provided.

Conservation of Natural Resources↗
PubMedDate not supplied

Relationship between pure Schistosoma haematobium infection in Upper Egypt and irrigation systems. Part 1: methods of study.

Four villages in Assiut Governorate were studied. They were matched for availability and time of introduction of medical services, the size of population and the socioeconomic status. One village had a basin system of irrigation. The other three villages had perennial irrigation introduced at different dates. A sketch map of each village was made showing the location of every house and the irrigation channels. Total coverage was intended in Gezirat El-Maabda (with basin irrigation) and Nazza Karar (with perennial irrigation-recently introduced). In El-Ghorayeb and Garf Sarhan (with older systems of perennial irrigation) systematic random samples were studied. The Study included a full, double check clinical examination of urine and stools samples and a social study. Data about educational level and activities that bring the individual in contact with canal water were recorded. Tables showing the age and sex distribution of the total population and the population studied in each village are presented and show validity of the samples taken from the population.

Adolescent↗
PubMedDate not supplied

Relationship between pure Schistosoma haematobium infection in Upper Egypt and irrigation systems. Part II: Host characteristics. The general prevalence of Schistosoma haematobium, age and sex distribution.

The epidemiology of bilharziasis was studied in four villages in Assiut Governorate. These villages were almost similar with respect to their socioeconomic conditions, modes of living, availability and date of introduction of medical services. The first village, Gezirat El-Maabda, has a basin system of irrigation. The other three villages had shifted to the perennial system of irrigation for three years in Nazza Karrar, 26 years in El-Ghorayeb and 95 years in Garf Sarhan and were similar with respect to proximity to water courses. So the only variable of importance between the four villages was the mode of irrigation. Bilharziasis was diagnosed by detection of eggs in urine or faeces. A definitive relationship between the prevalence of S. haematobium infection and the type of irrigation system was further documented. A low prevalence was found in Gezirat El-Maabda (2.95%). In the other three villages a much higher prevalence existed (31.9%, 46.2% & 38.9% in Nazza Karar, El-Ghorayeb and Garf Sarhan respectively). The higher prevalence of S. haematobium in Nazza Karar (31.9%) only three years after introduction of perennial irrigation was a disappointing finding. It can be considered as an evidence against the elaborate measures and precautions planned and incompletely implemented before or after the establishment of Aswan High Dam. Not a single case of S. mansoni was encountered during this study. As regards the age and sex distribution of S. haematobium in the three villages irrigated perennially, a steep rise started at the age group 5-9 years reaching a peak at the age group 10-14 years. In Gezirat El-Maabda the peak was reached at later age (15-19 years). The cause of this difference was explained. Males showed a higher rate of infection than females in almost all age groups of the four village studied.

Adolescent↗
PubMed1958

Relation between irrigation engineering and bilharziasis.

The author discusses the relation between irrigation systems and the transmission of bilharziasis, with special reference to the important part the irrigation engineer can play in checking the spread of the disease. He points out that, in the past, there has been little co-operation between health departments and public works agencies in respect of the setting-up of irrigation systems, and stresses the advantages to be gained from an active collaboration between malacologists, epidemiologists and irrigation engineers at the planning stage of irrigation schemes.The author also puts forward some suggestions for research on irrigation-system design and outlines the role of WHO in bilharziasis control.

Agriculture↗
PubMed2004

[Interactive effect of irrigation and nitrogen application on physiological characteristics of flag leaf and grain yield of winter wheat in dry years].

The field studies indicated that in dry years, both irrigation and nitrogen application had a marked yield increment effect, but irrigation played a more important role. Irrigation at jointing and booting stages could induce a higher grain yield, but irrigation at jointing, booting and grain-filling stages had a less yield increment effect if nitrogen was applied as base fertilizer. Insufficient irrigation reduced the nitrogen efficiency and yield, which could be compensated to some extent by increasing the nitrogen application rate. Only a suitable combination of irrigation and nitrogen application could effectively coordinate the relationship between yield components and increase grain yield.

Chlorophyll↗
PubMed2005

Nutrient balance in a paddy field with a recycling irrigation system.

We studied nutrient balance in a paddy field that had a recycling irrigation system and evaluated the effect of the irrigation system on nutrient balance during the irrigation period, from April to August 2002. Chemical fertilizer was the main input of phosphorus; the soil absorbed about 56% of it. The amount of nitrogen supplied by the irrigation system was higher than in a representative paddy field, and the amount of nitrogen fertilizer used was decreased because the irrigation water was partly reused. About 20% of applied nitrogen was lost by denitrification. The net outflows of phosphorus and nitrogen were -0.37 and -3.98 kg ha(-1), respectively. These results indicate that our study paddy field performed well in removing phosphorus and nitrogen compounds from runoff water. A recycling irrigation system can be considered an effective way of reducing the amounts of water and fertilizer used and reducing the outflow nutrients.

Conservation of Natural Resources↗
PubMed2005

[Effects of irrigation and nitrogen fertilization on winter wheat yield under straw mulch].

A field experiment was conducted on a Hongyou soil of Yangling to investigate the effects of irrigation and nitrogen fertilization on wheat yield under straw mulch. The results showed that under straw mulch, N fertilization contributed more to the increase of wheat yield than irrigation, because soil moisture condition was improved greatly. The interaction between irrigation and nitrogen fertilization was negative in no-mulch treatment, but positive under straw mulch. For dryland, more attention should be paid to the input of nutrients when straw mulch was applied. High moisture content in soil profile before sowing and sufficient N input were essential for good harvest when field was not mulched. Under straw mulch, the irrigation rate for a maximum yield was reduced, and the optimum time of irrigation was postponed. Wheat grain yield had no relation to the irrigation during jointing stage in both no-mulch and straw mulch treatments.

Fertilizers↗
PubMed2005

Environmental impact and health risks associated with greywater irrigation: a case study.

There is an increasing trend to use greywater for irrigation in households. This is partly due to the notion that greywater is of better quality than wastewater and therefore does not need extensive treatment beyond addressing public health issues. The aim of the study was to evaluate the environmental impact and health risks associated with the use of greywater for irrigation on a small private farm. Over a three-year period, each of three plots on a farm was irrigated with either freshwater, fertilized water, or greywater. Irrigation water and soil from the plots were analyzed for a wide range of chemical and microbial variables. Results suggest that greywater may be of similar quality to wastewater in several parameters such as BOD and faecal coliforms. For some other variables such as boron and surfactants, greywater may even be of worse quality than wastewater. Long-term irrigation of arid loess soil with greywater may result in accumulation of salts, surfactants and boron in the soil, causing changes in soil properties and toxicity to plants. Faecal coliforms did not survive in the soil. Treating greywater before using it for irrigation is recommended, even in places where this is not a requirement.

Agriculture↗
PubMed1981

[Whole-gut irrigation with mannitol in cirrhotic patients with gastro-intestinal bleeding. Changes in blood ammonia and aminoacids levels (author's transl)].

The purpose of the study was to examine the effects of whole gut mannitol irrigation on arterial blood ammonia and plasma aminoacids in cirrhotic patients with bleeding oesophageal varices and its influence on post-haemorrhagic encephalopathy. The 28 patients studied were divided at random into two groups: group I, non-irrigated (n = 16) and group II, irrigated (n = 12). In all cases bleeding was controlled by a Blakemore haemostatic tube which enabled irrigation to be performed in group II subjects. Four hours after starting irrigation a significant decrease in arterial blood ammonia became apparent in group II patients as compared with controls (p < 0.05). After 24 hours, blood ammonia had decreased in both groups but was significantly lower in group II patients than in group I patients (p < 0.01). No significant change in branched chain aminoacids to aromatic aminoacids molar ratio was observed in either group. Clinically, mannitol irrigation had a significantly (p < 0.01) favourable effect in preventing the development or aggravation of posthaemorrhagic encephalopathy, which suggests that toxic substances of intestinal origin, particularly ammonia, may intervene in the pathogenesis of this condition.

Amino Acids↗
PubMed1994

[Effects of high-level-manganese sewage irrigation on children's neurobehavior].

The neurobehavioral status was tested for 92 matched-pair pupils aged 11-13 in an area with high-level-manganese sewage irrigation and a control area. Results showed there was significant difference in manganese contents of drinking water between the area with sewage irrigation and the control area during 1990-1992, ranged 0.241-0.346 mg/L and 0.030-0.040 mg/L, respectively, with P < 0.01. Hair manganese content of children in the area with sewage irrigation (1.252 micrograms/g) was significantly higher than that in the control area (0.961 micrograms/g) with P < 0.01. Scores in digit span, Santa Ana manual dexterity, digit symbol, Benton visual retention test and pursuit aiming test for children in the area with sewage irrigation were significantly lower than those in the control area (P < 0.01). Hair manganese contents of the children in the area with sewage irrigation correlated negatively with most of those scores. It suggested high level of manganese in drinking water of the area with sewage irrigation might be an important factor affecting children's neurobehavioral changes.

Adolescent↗
PubMed1989

Electrochemical engineering approach to the irrigation of tooth canals under the influence of a vibrating file.

Doubt exists concerning the irrigation of secondary tooth canals when the vibration of a file introduced into the main root canal is superimposed on flow-through irrigation of the main canal. Depending on the type of commercial equipment used, the vibrations of the file are sonic or ultrasonic. We use the methodology of an electrochemical engineering approach in a study of the intensity of the irrigation of the secondary canals under the influence of sonic and ultrasonic vibrations of a file located at various heights in the main canal. The tooth canals are simulated by small electrochemical cells containing electrodes located at the end of cavities simulating the secondary canals. An electrochemical method is used to measure the mass transfer coefficients at these electrodes, a classical method in electrochemical engineering laboratories. The values of the mass transfer coefficients are representative of the importance of the irrigation of the electrodes. Thus they give a quantitative idea of the vibrations on the irrigation of secondary tooth canals. The work demonstrates the usefulness of the electrochemical engineering approach in contributing to the solution of a biomedical problem.

Electrochemistry↗
PubMed2026

Watershed-scale risk assessment of cadmium contamination in Chinese cropland soils: Dual pathways of irrigation input and flood-driven transport.

Irrigation and flood events serve as critical pathways for the transport of cadmium (Cd) from industrial sources into cropland soils at the watershed scale, constituting a major driver of widespread Cd contamination in China's cropland soil. This study evaluated the risk of Cd contamination in cropland soils across China's nine major river basins at the watershed scale, focusing on the contributions of irrigation and flood events, and conducted a sensitivity analysis of key risk factors. The assessment was conducted within a framework that considered factors including hazard, exposure, and vulnerability. The results revealed that numerous watersheds in southeastern China are exposed to dual pressures of Cd contamination risks in cropland soils, driven by both irrigation practices and flood events. Watersheds categorized as High-High, High-Moderate, or Moderate-High risk, reflecting combined Cd contamination risks from irrigation and flood, are vital to China's grain production, contributing 67.1 % of the national cropland area and 66.4 % of the grain yield. The study suggests localized strategies for managing cropland soils Cd contamination risks from irrigation and flood at the watershed scale in China, alongside strengthened cross-regional collaboration in southeastern China.

Cadmium↗
PubMed1988

Effect of irrigation and tourniquet application on aminoglycoside antibiotic concentrations in bone.

Preoperative antibiotics are an important measure taken to prevent infection in joint replacement surgery. The local availability of these antibiotics in the operative site is absolutely necessary to ensure adequate prophylaxis against contaminant bacteria. Because pulsatile-lavage rapid-recovery systems have become a routine technique of bone preparation in joint reconstruction, we chose to study the effect of these systems on local antibiotic concentrations. We further investigated the effect of irrigation with and without use of a limb tourniquet. For our study, we obtained 23 bone specimens in 16 patients undergoing joint reconstruction (14) or amputation (2). The patients were classified into one of four groups based on whether a tourniquet was applied during the procedure and whether the bone specimens were irrigated. In addition, matched blood samples were obtained to establish that therapeutic serum levels were achieved. Nine patients contributed 13 bone specimens, which underwent vigorous irrigation in vitro. None of these specimens had detectable levels of antibiotics, regardless of whether a tourniquet was used. Seven patients yielded 10 bone specimens, which were not irrigated. Five of these seven patients had detectable levels of antibiotics. In addition, the specimens from limbs without tourniquets had levels that averaged 0.51 microgram/ml while those with tourniquets averaged below 0.2 microgram/ml. Therefore, the use of vigorous irrigation in bone preparation has a significant deleterious effect on the local presence of previously administered systemic antibiotics. This effect is compounded if the operative site is isolated from continuous blood flow by use of a tourniquet. We therefore recommend that additional measures be taken to ensure that adequate antibiotic levels are present.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

A scintigraphic analysis of colonic movement in patients with colostomy: changes of colonic transit time after acquaintance with irrigation.

For the purpose of making a functional assessment of colostomy irrigation, eight patients were examined. Group A was composed of four patients whose experience of irrigation was less than one year. Group B was composed of four patients who had undergone irrigation for more than two years. The capacity of the remnant colon was determined by a barium enema. Next, 74 MBq of milking technetium 99 diethylene triamine penta-acetic acid (99mTc-DTPA) was instilled with a predetermined amount of water (37 degrees C). A dynamic scan was performed for 45 min. The mean evacuation time of Groups A and B were 6 min 56 s +/- 2 min 33 s and 13 min 27 s +/- 10 min 50 s, respectively. The mean half emptying time of Groups A and B were 142.5 s +/- 7.9 s and 309.0 s +/- 181.9 s. The results suggest that the remnant colon may be habituated with irrigation. Colostomy irrigation which uses a single instillation of a measured volume of tepid water is recommended.

Adult↗