Tag Archives: health effects

Inorganic Arsenic Exposure from US Rice and Total Water Intake

Madhavi Mantha, Edward Yeary, John Trent, Patricia A. Creed, Kevin Kubachka, Traci Hanley, Nohora Shockey, Douglas Heitkemper, Joseph Caruso, Jianping Xue, Glenn Rice, Larry Wymer, and John T. Creed. Estimating Inorganic Arsenic Exposure from U.S. Rice and Total Water Intakes Environmental Health Perspectives https://doi.org/10.1289/EHP418

BACKGROUND: Among nonoccupationally exposed U.S. residents, drinking water and diet are considered primary exposure pathways for inorganic arsenic
(iAs). In drinking water, iAs is the primary form of arsenic (As), while dietary As speciation techniques are used to differentiate iAs from less toxic arsenicals in food matrices.

OBJECTIVES: Our goal was to estimate the distribution of iAs exposure rates from drinking water intakes and rice consumption in the U.S. population
and ethnic- and age-based subpopulations.

METHODS: The distribution of iAs in drinking water was estimated by population, weighting the iAs concentrations for each drinking water utility in
the Second Six-Year Review data set. To estimate the distribution of iAs concentrations in rice ingested by U.S. consumers, 54 grain-specific, production-weighted composites of rice obtained from U.S. mills were extracted and speciated using both a quantitative dilute nitric acid extraction and speciation
(DNAS) and an in vitro gastrointestinal assay to provide an upper bound and bioaccessible estimates, respectively. Daily drinking water intake
and rice consumption rate distributions were developed using data from the What We Eat in America (WWEIA) study.

RESULTS: Using these data sets, the Stochastic Human Exposure and Dose Simulation (SHEDS) model estimated mean iAs exposures from drinking
water and rice were 4.2 ug/day and 1.4 ug/day, respectively, for the entire U.S. population. The Tribal, Asian, and Pacific population exhibited the
highest mean daily exposure of iAs from cooked rice (2.8 ug/day); the mean exposure rate for children between ages 1 and 2 years in this population
is 0.104 ug/kg body weight (BW)/day.

CONCLUSIONS: An average consumer drinking 1.5 L of water daily that contains between 2 and 3 ng iAs/mL is exposed to approximately the same
amount of iAs as a mean Tribal, Asian, and Pacific consumer is exposed to from rice. 

Cyanobacterial Toxins, Toxicological Effects, Numerical Limits in Drinking Water

Miller TR, Beversdorf LJ, Weirich CA, Bartlett SL. Cyanobacterial Toxins of the Laurentian Great Lakes, Their Toxicological Effects, and Numerical Limits in Drinking Water. Marine drugs. 2017 Jun 2;15(6). pii: E160. doi: 10.3390/md15060160.

Cyanobacteria are ubiquitous phototrophic bacteria that inhabit diverse environments across the planet. Seasonally, they dominate many eutrophic lakes impacted by excess nitrogen (N) and phosphorus (P) forming dense accumulations of biomass known as cyanobacterial harmful algal blooms or cyanoHABs. Their dominance in eutrophic lakes is attributed to a variety of unique adaptations including N and P concentrating mechanisms, N₂ fixation, colony formation that inhibits predation, vertical movement via gas vesicles, and the production of toxic or otherwise bioactive molecules. While some of these molecules have been explored for their medicinal benefits, others are potent toxins harmful to humans, animals, and other wildlife known as cyanotoxins. In humans these cyanotoxins affect various tissues, including the liver, central and peripheral nervous system, kidneys, and reproductive organs among others. They induce acute effects at low doses in the parts-per-billion range and some are tumor promoters linked to chronic diseases such as liver and colorectal cancer. The occurrence of cyanoHABs and cyanotoxins in lakes presents challenges for maintaining safe recreational aquatic environments and the production of potable drinking water. CyanoHABs are a growing problem in the North American (Laurentian) Great Lakes basin. This review summarizes information on the occurrence of cyanoHABs in the Great Lakes, toxicological effects of cyanotoxins, and appropriate numerical limits on cyanotoxins in finished drinking water.

Manganese in Drinking Water and Cognitive Abilities

Rahman SM, Kippler M, Tofail F, Bölte S, Derakhshani Hamadani J, Vahter M. Manganese in Drinking Water and Cognitive Abilities and Behavior at 10 Years of Age: A Prospective Cohort Study. Environmental health perspectives. 2017 May 26;125(5):057003. doi: 10.1289/EHP631.

BACKGROUND: Cross-sectional studies have indicated impaired neurodevelopment with elevated drinking water manganese concentrations (W-Mn), but potential susceptible exposure windows are unknown.

OBJECTIVES: We prospectively evaluated the effects of W-Mn, from fetal life to school age, on children’s cognitive abilities and behavior.

METHODS: We assessed cognitive abilities and behavior in 1,265 ten-year-old children in rural Bangladesh using the Wechsler Intelligence Scale for Children (WISC-IV) and the Strengths and Difficulties Questionnaire (SDQ), respectively. Manganese in drinking water used during pregnancy and by the children at 5 y and 10 y was measured using inductively coupled plasma mass spectrometry.

RESULTS: The median W-Mn was (range 0.001-6.6) during pregnancy and  at 10 y. In multivariable-adjusted linear regression analyses, restricted to children with low arsenic (As) exposure, none of the W-Mn exposures was associated with the children’s cognitive abilities. Stratifying by gender (p for interaction in general  showed that prenatal W-Mn was positively associated with cognitive ability measures in girls but not in boys. W-Mn at all time points was associated with an increased risk of conduct problems, particularly in boys (range 24-43% per mg/L). At the same time, the prenatal W-Mn was associated with a decreased risk of emotional problems [odds ratio (OR)=0.39 (95% CI: 0.19, 0.82)] in boys. In girls, W-Mn was mainly associated with low prosocial scores [prenatal W-Mn: OR=1.48 (95% CI: 1.06, 1.88)].

CONCLUSIONS: Elevated prenatal W-Mn exposure was positively associated with cognitive function in girls, whereas boys appeared to be unaffected. Early life W-Mn exposure appeared to adversely affect children’s behavior. 

Ohio Arsenic Study Exposure Assessment Inadequate, Inconclusive

Alarming as this study may appear, it is simply another in a long line of weak ecologic studies examining birth outcomes and drinking water that rely on an inadequate exposure assessment. The exposure was not directly measured and is unknown. In studies such as this statistical manipulations simply cannot reliably compensate for an inadequate assessment of contaminant exposure.

Almberg KS, Turyk ME, Jones RM, Rankin K, Freels S, Graber JM, Stayner LT. Arsenic in drinking water and adverse birth outcomes in Ohio. Environ Res. 2017 May 15;157:52-59. doi: 10.1016/j.envres.2017.05.010.

BACKGROUND: Arsenic in drinking water has been associated with adverse reproductive outcomes in areas with high levels of naturally occurring arsenic. Less is known about the reproductive effects of arsenic at lower levels.

OBJECTIVES: This research examined the association between low-level arsenic in drinking water and small for gestational age (SGA), term low birth weight (term LBW), very low birth weight (VLBW), preterm birth (PTB), and very preterm birth (VPTB) in the state of Ohio.

METHODS: Exposure was defined as the mean annual arsenic concentration in drinking water in each county in Ohio from 2006 to 2008 using Safe Drinking Water Information System data. Birth outcomes were ascertained from the birth certificate records of 428,804 births in Ohio from the same time period. Multivariable generalized estimating equation logistic regression models were used to assess the relationship between arsenic and each birth outcome separately. Sensitivity analyses were performed to examine the roles of private well use and prenatal care utilization in these associations.

RESULTS: Arsenic in drinking water was associated with increased odds of VLBW (AOR 1.14 per µg/L increase; 95% CI 1.04, 1.24) and PTB (AOR 1.10; 95% CI 1.06, 1.15) among singleton births in counties where <10% of the population used private wells. No significant association was observed between arsenic and SGA, or VPTB, but a suggestive association was observed between arsenic and term LBW.

CONCLUSIONS: Arsenic in drinking water was positively associated with VLBW and PTB in a population where nearly all (>99%) of the population was exposed under the current maximum contaminant level of 10µg/L. Current regulatory standards may not be protective against reproductive effects of prenatal exposure to arsenic.

Manganese Exposure and Neurotoxic Effects in Children

Bjørklund G, Chartrand MS, Aaseth J. Manganese exposure and neurotoxic effects in children. Environ Res. 2017 May;155:380-384. doi: 10.1016/j.envres.2017.03.003. Epub 2017 Mar 10.

Manganese (Mn) is the fifth most abundant metal on earth. Although it is a well understood essential trace element, in excess, Mn is neurotoxic. Initial toxic symptoms associated with Mn are of psychiatric nature and are clinically defined as locura manganica. Neurological signs of Mn toxicity include dystonia, progressive bradykinesia, and disturbance of gait, slurring, and stuttering of speech with diminished volume. Studies indicate that children who ingested Mn in the drinking water (WMn) at or above a level of 0.241mg/L for a minimum of three years performed more poorly in school as measured by mastery of language, mathematics, and in their overall grade average. The Mn-exposed children also performed more poorly on a battery of neurobehavioral tests. It was also found a significant association between higher WMn and lower cognitive performance, verbal function, and full-scale intelligence quotient (IQ) scores. Young children appear to make up a vulnerable group in exposed populations. Toxicity of WMn is a problem particularly in areas of industrial waste or where Mn is leaching from the soil into public drinking water. Practical and cost-effective approaches are available to remove Mn from drinking water. It is crucial to protect developing brains against Mn toxicity.

China Air Pollution Study has Serious Weaknesses; Non-conclusive

Peng Yin, Guojun He, Maoyong Fan, Kowk Yan Chiu, Maorong Fan, Chang Liu, An Xue, Tong Liu, Yuhang Pan, Quan Mu, Maigeng Zhou. Particulate air pollution and mortality in 38 of China’s largest cities: time series analysis. BMJ 2017;356:j667 doi: https://doi.org/10.1136/bmj.j667

The findings of this particular study (click here) and been seriously questioned (click here). If not considered, cigarette smoking is a huge confounding factor in any study involving the respiratory system. Confidence limits on the analysis must be considered when evaluating data.

Coffee consumption found to be safe

Chrysant SG The impact of coffee consumption on blood pressure, cardiovascular disease and diabetes mellitus. Expert review of cardiovascular therapy. 2017 Feb 3:1-6. doi: 10.1080/14779072.2017.1287563.

Introduction: Coffee is the most widely consumed beverage, next to water. However, there has been a long-standing controversy regarding its safety on blood pressure (BP) and cardiovascular disease (CVD) and intuitively, physicians dissuaded their patients from coffee drinking.

Areas covered: This controversy was, primarily, based on older prospective studies or case reports, which showed a positive association of coffee drinking with the incidence of hypertension and CVD. In contrast to these reports, recent, well controlled, studies have demonstrated either a neutral or beneficial effect of moderate coffee consumption (3-4 cups/day), on BP, CVD, heart failure (HF), cardiac arrhythmias, or diabetes mellitus (DM). For the preparation of this special report, an English language focused search of the Medline database was conducted between 2010 and 2016 on studies with data on effect on the coffee consumption in patients with high BP, CVD, HF, cardiac arrhythmias or DM. Of the 94 abstracts reviewed, 34 pertinent papers were selected, and the findings from these papers together with collateral literature will be discussed in this special report.

Expert commentary: Based on the evidence from these studies, coffee consumption in moderation, is safe and is beneficial in both healthy persons as well as patients with high BP, CVD, HF, cardiac arrhythmias or DM. Therefore, coffee restriction is not warranted for these patients, although some caution should be exercised.