Tag Archives: pesticides

Review of Pesticide Standards Worldwide

Li Z, Jennings A. Worldwide Regulations of Standard Values of Pesticides for Human Health Risk Control: A Review. International journal of environmental research and public health. 2017 Jul 22;14(7). pii: E826. doi: 10.3390/ijerph14070826.

The impact of pesticide residues on human health is a worldwide problem, as human exposure to pesticides can occur through ingestion, inhalation, and dermal contact. Regulatory jurisdictions have promulgated the standard values for pesticides in residential soil, air, drinking water, and agricultural commodity for years. Until now, more than 19,400 pesticide soil regulatory guidance values (RGVs) and 5400 pesticide drinking water maximum concentration levels (MCLs) have been regulated by 54 and 102 nations, respectively. Over 90 nations have provided pesticide agricultural commodity maximum residue limits (MRLs) for at least one of the 12 most commonly consumed agricultural foods. A total of 22 pesticides have been regulated with more than 100 soil RGVs, and 25 pesticides have more than 100 drinking water MCLs. This research indicates that those RGVs and MCLs for an individual pesticide could vary over seven (DDT drinking water MCLs), eight (Lindane soil RGVs), or even nine (Dieldrin soil RGVs) orders of magnitude. Human health risk uncertainty bounds and the implied total exposure mass burden model were applied to analyze the most commonly regulated and used pesticides for human health risk control. For the top 27 commonly regulated pesticides in soil, there are at least 300 RGVs (8% of the total) that are above all of the computed upper bounds for human health risk uncertainty. For the top 29 most-commonly regulated pesticides in drinking water, at least 172 drinking water MCLs (5% of the total) exceed the computed upper bounds for human health risk uncertainty; while for the 14 most widely used pesticides, there are at least 310 computed implied dose limits (28.0% of the total) that are above the acceptable daily intake values. The results show that some worldwide standard values were not derived conservatively enough to avoid human health risk by the pesticides, and that some values were not computed comprehensively by considering all major human exposure pathways.

Organochlorine Pesticides in Surface Water, Wuhan, China

Cui L, Wei L, Wang J. Residues of organochlorine pesticides in surface water of a megacity in central China: seasonal-spatial distribution and fate in Wuhan. Environmental science and pollution research international 2016 Oct 31.

Surface water quality closely correlating with human health suffered increasing organochlorine pesticide (OCP) pollution due to the intensive anthropogenic activities in megacities. In the present study, 112 water samples collected from 14 lakes and 11 drinking water source sites in Wuhan were detected for the residues of OCPs in November 2013 and July 2014, respectively. The ΣOCPs ranged from 5.61 to 13.62 ng L-1in summer with the maximum value in Yezhi Lake and 3.18 to 7.73 ng L-1 in winter with the highest concentration in Yandong Lake. Except dichlorodiphenyltrichloroethanes (DDTs), OCP concentrations in summer were significantly higher than those in winter mostly due to the non-point source pollution including land runoff in summer. Source apportionment of hexachlorocyclohexanes (HCHs) and DDTs revealed the historical use of technical HCH and lindane and the new input of DDT, respectively. The spatial distribution of OCPs was not uniform in the surface water of Wuhan because of the significant influence of land development and fishery. The risk assessments showed the heptachlor, and heptachlor epoxide in most sampling sites exceeded the threshold set by the European Union, indicating the possible adverse effects for aquatic lives. Negligible non-carcinogenic risks for drinking and bathing as well as carcinogenic risks for bathing were found in the surface water. However, the total carcinogenic risks of all OCPs (∑Rs) caused by drinking in summer were higher than the safe level of 10-7 in all sampling sites. It was implied that the surface water in Wuhan was not safe for directly drinking without effective purification.

Organochlorine Pesticides and PCBs in Surface Water around Beijing, China

Shao Y, Yang G, Liu W, Ma L, Luo M, Xu D. Organochlorine pesticides and polychlorinated biphenyls in surface water around Beijing. Environmental science and pollution research international. 2016 Sep 23.

Contaminant concentrations, sources, seasonal variation, and eco-toxicological risk of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in surface water around Beijing from summer to winter in 2015 and 2016 were investigated. The concentrations of ∑OCPs and ∑PCBs ranged from 9.81 to 32.1 ng L-1 (average 15.1 ± 7.78 ng L-1) and from 7.41 to 54.5 ng L-1 (average 21.3 ± 1.87 ng L-1), respectively. Hexachlorocyclohexane (HCHs) were the dominated contamination both in aqueous and particulate phase. For PCBs, lower chlorinated PCBs were the major contaminants. Compositions of HCHs, dichlorodiphenyltrichloroethane (DDTs), and PCBs indicated that the sources of OCPs and PCBs in water were due to historical usage in the study areas. For OCPs, there was an obvious variation among three seasons, while insignificant change was shown for PCBs. Water quality standards for China’s surface water were not exceeded in this study. Concentrations at Miyun Reservoir, the primary source of drinking water to Beijing, when compared to the USEPA’s criterion for cancer risk was below the level of risk.

Pesticide Exposure and Human Health Effects

Kim KH, Kabir E, Jahan SA. Exposure to pesticides and the associated human health effects. The Science of the total environment. 2016 Sep 7. pii: S0048-9697(16)31926-X. doi: 10.1016/j.scitotenv.2016.09.009.

Pesticides are used widely to control weeds and insect infestation in agricultural fields and various pests and disease carriers (e.g., mosquitoes, ticks, rats, and mice) in houses, offices, malls, and streets. As the modes of action for pesticides are not species-specific, concerns have been raised about environmental risks associated with their exposure through various routes (e.g., residues in food and drinking water). Although such hazards range from short-term (e.g., skin and eye irritation, headaches, dizziness, and nausea) to chronic impacts (e.g., cancer, asthma, and diabetes), their risks are difficult to elucidate due to the involvement of various factors (e.g., period and level of exposure, type of pesticide (regarding toxicity and persistence), and the environmental characteristics of the affected areas). There are no groups in the human population that are completely unexposed to pesticides while most diseases are multi-causal to add considerable complexity to public health assessments. Hence, development of eco-friendly pesticide alternatives (e.g., EcoSMART) and Integrated Pest Management (IPM) techniques is desirable to reduce the impacts of pesticides. This paper was hence organized to present a comprehensive review on pesticides with respect to their types, environmental distribution, routes of exposure, and health impacts.

Pesticide Residues in Drinking Water, Ethiopia

Mekonen S, Argaw R, Simanesew A, Houbraken M, Senaeve D, Ambelu A, Spanoghe P. Pesticide residues in drinking water and associated risk to consumers in Ethiopia. Chemosphere 2016 Aug 5;162:252-260. doi: 10.1016/j.chemosphere.2016.07.096.

Access to safe and reliable drinking water is vital for a healthy population. However, surface water may be contaminated with pesticides because of the nearby agricultural areas as well as from household application. Water samples were collected from water sources in Jimma zone and Addis Ababa, Ethiopia. The extraction and clean up of the samples were undertaken using liquid-solid and liquid-liquid methods. Human exposure was assessed by calculating the estimated daily intake (EDI) of pesticides in water and compared with the acceptable daily intake (ADI) and the acute reference dose (ARfD). The mean concentrations of 2,4-D, malathion, diazinon and fenpropimorph were 1.59-13.90 μg/l and 0.11-138 µg/l in Jimma and Addis Ababa water sources, respectively. The residue level of some of the pesticides were above the European drinking water guide line values, which is an indication of an illegal use of pesticides in the study areas. Concerning human health risk estimation, there was no acute risk (EDI < ARfD). However, chronic risks to human health were observed from exposure to diazinon and fenpropimorph (EDI > ADI) for Jimma and Addis Ababa populations, respectively. A comprehensive monitoring is required to reduce the level of pesticide residues in the water and to minimize particularly the long term human health risks.

Nitenpyram Degradation in Finished Drinking Water

Noestheden M, Roberts S, Hao C. Nitenpyram degradation in finished drinking water. Rapid Communication Mass Spectrom. 2016 Jul 15;30(13):1653-61. doi: 10.1002/rcm.7581.

RATIONALE: Neonicotinoid pesticides and their metabolites have been indicated as contributing factors in the decline of honey bee colonies. A thorough understanding of neonicotinoid toxicity requires knowledge of their metabolites and environmental breakdown products. This work investigated the rapid degradation of the neonicotinoid nitenpyram in finished drinking water.

METHODS: Nitenpyram reaction products were characterized using liquid chromatography/quadrupole time-of-flight mass spectrometry (LC/QTOFMS). A software algorithm that compared degraded and control samples was utilized to facilitate efficient data reduction. Fragmentation pathways for six reaction products and nitenpyram were proposed using predictive software and manual product ion analysis.

RESULTS: This study showed that nitenpyram degradation in unpreserved finished drinking water was likely the result of oxidation, hydrolysis and reaction with Cl2 . Structures for six nitenpyram reaction products were proposed that suggest the C9/C11 olefin as the key reactive site.

CONCLUSIONS: Similarities between the identified nitenpyram reaction products and imidacloprid metabolites highlight the importance of this study, as the toxicity of neonicotinoids to pollinators has been linked to their metabolites. Based on the proposed reaction mechanisms, the identified nitenpyram reaction products in finished drinking water could also be present in the environment and water treatment facilities. As such, identifying these degradation products will aid in evaluating the environmental impact of neonicotinoid pesticides.

Manganese in Drinking Water Increases from Aerial Spraying of Mancozeb

Keep in mind that the presence of manganese in drinking water does not necessarily mean that a WHO health guideline is needed. Action can be taken at this locality to lower manganese exposure to below the level of health concern by meeting the existing secondary MCL.

Berna van Wendel de Joode, Benoit Barbeau, Maryse F. Bouchard, Ana María Mora, Åsa Skytt, Leonel Córdoba, Rosario Quesada, Thomas Lundh, Christian H. Lindh, Donna Mergler. Manganese concentrations in drinking water from villages near banana plantations with aerial mancozeb spraying in Costa Rica: Results from the Infants’ Environmental Health Study. Environmental Pollution, Volume 215, August 2016, Pages 247-257.

Elevated manganese (Mn) in drinking water has been reported worldwide. While, naturally occurring Mn in groundwater is generally the major source, anthropogenic contamination by Mn-containing fungicides such as mancozeb may also occur. The main objective of this study was to examine factors associated with Mn and ethylenethiourea (ETU), a degradation product of mancozeb, in drinking water samples from villages situated near banana plantations with aerial spraying of mancozeb. Drinking water samples (n = 126) were obtained from 124 homes of women participating in the Infants’ Environmental Health Study (ISA, for its acronym in Spanish), living nearby large-scale banana plantations. Concentrations of Mn, iron (Fe), arsenic (As), lead (Pb), cadmium (Cd) and ethylenethiourea (ETU), a degradation product of mancozeb, were measured in water samples. Only six percent of samples had detectable ETU concentrations (limit of detection (LOD) = 0.15 μg/L), whereas 94% of the samples had detectable Mn (LOD = 0.05 μg/L). Mn concentrations were higher than 100 and 500 μg/L in 22% and 7% of the samples, respectively. Mn was highest in samples from private and banana farm wells. Distance from a banana plantation was inversely associated with Mn concentrations, with a 61.5% decrease (95% CI: −97.0, −26.0) in Mn concentrations for each km increase in distance. Mn concentrations in water transported with trucks from one village to another were almost 1000 times higher than Mn in water obtained from taps in houses supplied by the same well but not transported, indicating environmental Mn contamination. Elevated Mn in drinking water may be partly explained by aerial spraying of mancozeb; however, naturally occurring Mn in groundwater, and intensive agriculture may also contribute. Drinking water risk assessment for mancozeb should consider Mn as a health hazard. The findings of this study evidence the need for health-based World Health Organization (WHO) guidelines on Mn in drinking water.