Residual herbicides used in the production of soybean [Glycine max (L.) Merr] and corn (Zea mays L.) are often detected in surface runoff at concentrations exceeding their maximum contaminant levels (MCL) or health advisory levels (HAL). With the advent of transgenic, glyphosate-tolerant soybean and glufosinate-tolerant corn this concern might be reduced by replacing some of the residual herbic...

background: the purpose of study was to evaluate and compare chemical quality of iranian bottled drinking water reported on manufacturer's labeling and standards. methods: this study was a cross-sectional descriptive study and done during july to december 2008. the bottled mineral water collected from shops randomly were analyzed for all parameters address on manufacturer's labeling and the res...

concentrations of heavy metals (ni, co, zn, cd, pb and cu) in the reservoir of shahid rajaeidam, one of the main water reservoirs in north part of iran, were determined using a differential pulse polarography(metrohm 797 va) and compared with the national and international specified maximum contaminant levels(mcl) for different purposes of water use. the results showed that concentrations of cd...

hlorine is the most widely used oxidant in the United States for water disinfection. But chlorine reacts with the natural organic matter (NOM) that remains after treatment and forms halogenated by-products. Only some of these by-products have been identified, such as trihalomethanes (THMs) and haloacetic acids (HAAs), which are suspected to be human carcinogens. In 1979 the US Environmental Pro...

A method has been established to measure the maximum acceptable background noise level (BNL) for a listener, while listening to speech at the most comfortable listening level (MCL). The acceptable noise level (ANL) is the difference between BNL and MCL. In the present study, the ANL procedure was used to measure acceptance of noise, first, in the presence of speech at MCL and, then, for speech ...

BACKGROUND Private water systems are more likely to have nitrate levels above the maximum contaminant level (MCL). Pregnant women are considered vulnerable to the effects of exposure to high levels of nitrates in drinking water due to their altered physiological states. The level of methemoglobin in the blood is the biomarker often used in research for assessing exposure to nitrates. The object...

In greater Augusta of central Maine, 53 out of 1093 (4.8%) private bedrock well water samples from 1534 km(2) contained [U] >30 μg/L, the U.S. Environmental Protection Agency's (EPA) Maximum Contaminant Level (MCL) for drinking water; and 226 out of 786 (29%) samples from 1135 km(2) showed [Rn] >4,000 pCi/L (148 Bq/L), the U.S. EPA's Alternative MCL. Groundwater pH, calcite dissolution and redo...

This paper uses a life-cycle assessment (LCA) framework to characterize comparative environmental impacts from the use of virgin aggregate and recycled materials in roadway construction. To evaluate site-specific human toxicity potential (HTP) in a more robust manner, metals release data from a demonstration site were combined with an unsaturated contaminant transport model to predict long-term...

To protect human health, atrazine concentrations in finished municipal drinking water must not exceed a maximum contaminant level (MCL) of 3 microg/L, as determined by a specific monitoring regime mandated by the United States Environmental Protection Agency. Atrazine levels were monitored along tile-fed drainage ditches draining to a major drinking water source and used to predict MCL exceedan...

In many countries, public concern over the deterioration of groundwater quality from nitrate contamination has grown significantly in recent years. This concern has focused increasingly on anthropogenic sources as the potential cause of the problem. Evidence indicates that the nitrate (NO3) levels routinely exceed the maximum contaminant level (MCL) of 10 mg/l NO3-N in many aquifer systems that...