The Rise and Decline of Temik: Once hailed as a miracle pest killer and still warmly regarded by farmers, it is being investigated, denounced, and threatened with federal controls

Herbal and dietary supplement induced liver injury: Highlights from the recent literature

Herbal-induced liver injury (HILI) is an important and increasingly concerning cause of liver toxicity, and this study presents recent updates to the literature. An extensive literature review was conducted encompassing September 2019 through March 2021. Studies with clinically significant findings were analyzed and included in this review. We emphasized those studies that provided a causality assessment methodology, such as Roussel Uclaf Causality Assessment Method scores. Our review includes reports of individual herbals, including Garcinia cambogia, green tea extract, kratom as well as classes such as performance enhancing supplements, Traditional Chinese medicine, Ayurvedic medicine and herbal contamination. Newly described herbals include ashwagandha, boldo, skyfruit, and 'Thermo gun'. Several studies discussing data from national registries, including the United States Drug-Induced Liver Injury (DILI) Network, Spanish DILI Registry, and Latin American DILI Network were incorporated. There has also been a continued interest in hepatoprotection, with promising use of herbals to counter hepatotoxicity from anti-tubercular medications. We also elucidated the current legal conversation surrounding use of herbals by presenting updates from the Federal Drug Administration. The highlights of the literature over the past year indicate interest in HILI that will continue as the supplement industry in the United States grows.

Lowland tapir exposure to pesticides and metals in the Brazilian Cerrado

Abstract ContextThe Cerrado is a Global Biodiversity Hotspot as well as Brazil’s main frontier for large-scale agriculture and livestock production, making it one of the most threatened biomes in the country. Brazil is one of the biggest consumers of pesticides in the world and allows the use of chemicals that are banned in many other countries due to their adverse health effects in a wide range of species, including humans. AimsThis study aimed to assess pesticide and metal exposure of the lowland tapir – a threatened, large herbivorous mammal – to support future studies of the role of these chemicals in tapir health, survivorship, and population viability. MethodsFoot pad, proboscis, stomach contents, liver, bone, and nail samples were obtained from tapir carcasses found along highways (n=87). (i) Atomic absorption spectrophotometry (AAS) was used to detect metals in bone, nail and liver tissue; (ii) gas chromatography – nitrogen phosphorous detector (GC-NPD) to detect organophosphates in liver and skin; and (iii) high performance liquid chromatography – ultraviolet (HPLC-UV) to detect pyrethroids and carbamates in stomach contents. Key resultsTwo carbamates (aldicarb and carbaryl), three organophosphates (diazinon, malathion, and mevinphos), two pyrethroids (deltamethrin and permethrin), and two toxic metals (cadmium and lead) were detected in different tapir tissue samples, some at concentrations high enough to cause adverse health effects. In 90% of roadkill tapirs that were subjected to a full post-mortem examination (n=25), macroscopic alterations of liver and/or kidney tissue were observed. ConclusionsThis study provides the first report to date of the detection of pesticides and metals in lowland tapirs. ImplicationsSome of the reported pesticide concentrations exceed environmental safety thresholds. Consequently, results from this study raise concerns over potential adverse health effects in tapirs that could lead to population level impacts, thus requiring further investigation.

Delivery

Enthusiasm greeted the development of synthetic organic insecticides in the mid-twentieth century, only to see this give way to dismay and eventually scepticism and outright opposition by some. Regardless of how anyone feels about this issue, insecticides and other pesticides have become indispensable, which creates something of a dilemma. Possibly as a result of the shift in public attitude towards insecticides, genetic engineering of microbes was first met with scepticism and caution among scientists. Later, the development of genetically modified crop plants was met with an attitude that hardened into both acceptance and hard-core resistance. Transgenic insects, which came along at the dawn of the twenty-first century, encountered an entrenched opposition. Those of us responsible for studying the protection of crops have been affected more or less by these protagonist and antagonistic positions, and the experiences have often left one thoughtfully mystified as decisions are made by non-participants. Most of the issues boil down to concerns over delivery mechanisms.

Environmental consequences of modern production agriculture: How can alternative agriculture address these issues and concerns?

Modern large-scale conventional agriculture with intensive monoculture and row-cropping practices often results in unacceptable soil erosion and runoff and in associated losses of nutrients and pesticides. It also adversely affects wildlife. Sediment from erosion is the greatest pollutant of surface water in the United States and is a major carrier of agrichemicals into the water system. Conservation tillage practices can significantly reduce soil losses in modern production systems, but pollution of surface and groundwaters from runoff and associated potential for increased use of pesticides may still present a hazard. Erosion can be reduced to tolerable levels by the use of crop rotations, meadow crops, and mulch tillage, as commonly used in alternative agriculture. These cultural practices also result in diversity in crop types and in smaller fields, with possible benefit to many wildlife species. Chemical threats to the environment and to wildlife are reduced because synthetic chemicals are used sparingly or not at all.

Occupational exposure to genotoxic agents

Millions of workers in the United States are potentially exposed each year to hazardous chemicals, dusts, or fibers in occupational settings. Some of these agents are genotoxic and may cause genetic alterations in the somatic or germ cells of exposed workers. Such alterations, if they occur in proto-oncogenes or tumor suppressor genes, which are involved in controlling cell growth or differentiation, may lead to the development of cancer. Genetic alterations in germ cells may also lead to reproductive failure or genetic disorders in subsequent generations. It has been estimated that occupational exposure accounts for 4% of all human cancers and up to 30% of cancer among blue-collar workers. Approximately 20,000 cancer deaths each year are attributable to occupational exposure in the United States. Occupational cancer and reproductive abnormalities have been listed on the National Occupational Research Agenda master list of research priorities as major occupational diseases and injuries.

Toxic epidemics caused by alimentary exposure to pesticides: a review

Toxic epidemics have become a serious problem during the twentieth century, due mainly to the huge expansion over the last 50 years of the chemical industry, which has placed tens of thousands of new synthetic organic compounds in the human environment. In the particular case of chemical pesticides, their undiscriminating, widespread use, and harmful potential has been demonstrated by the epidemics generated by accidental contamination by pesticides of foods consumed by man, resulting in high mortality and morbidity rates. We have analysed the main characteristics of 63 outbreaks of toxicity caused by alimentary exposure to pesticides described in the scientific literature of this century, with the aim of increasing knowledge and understanding of the factors that are conducive to them or that trigger their onset. Such episodes are good indicators of the incorrect use of these products and serve to demonstrate failures of the available safety systems. We conclude by identifying some preventive measures that could be used to avoid their future repetition.

Immunosuppression by aldicarb of T cell responses to antigen-specific and polyclonal stimuli results from defective IL-1 production by the macrophages

In the present study we investigated the immunomodulatory effects of aldicarb, a carbamate pesticide, on T cells activated by a number of different ways. When C3H mice were injected intraperitoneally with a single dose of Aldicarb, 0.005-50 micrograms/kg body wt, and their spleen cells were stimulated with T cell mitogens such as concanavalin A (ConA)3 or anti-CD3 monoclonal antibodies (mAb), a decreased responsiveness was detected when compared to the control mice. Aldicarb administered at concentrations less than 0.005 microgram/kg body wt failed to cause significant immunosuppression. Interestingly, when purified T cells from immunosuppressive doses of aldicarb-treated mice were stimulated with ConA in the presence of irradiated control macrophages, the defective T cell response was no longer demonstrable. Also, purified control T cells stimulated with ConA in the presence of irradiated macrophages from aldicarb-treated mice showed decreased responsiveness. Similar observations were made using anti-CD3 mAb to activate the T cells, inasmuch as whole spleen cells from aldicarb-treated mice showed decreased responsiveness to anti-CD3 stimulation, whereas purified T cells in the presence of irradiated control macrophages showed normal reactivity. The fact that aldicarb did not directly affect the T cell functions was further confirmed by stimulating purified T cells from aldicarb-treated mice with phorbol myristate acetate and calcium ionophore, a response which is independent of the accessory cells and which was found to be normal in aldicarb-treated mice. It was observed that the macrophages from aldicarb-treated mice demonstrated a decreased capacity to stimulate conalbumin-specific T helper cell clone, D10.G4, and when activated produced decreased amounts of IL-1 when compared to control macrophages. Also, the decreased stimulation of D10.G4 clone by aldicarb-treated macrophages was reconstituted when exogenous recombinant IL-1 was added to the cultures. These data together suggested that aldicarb affects the macrophage functions by interfering with IL-1 production and that it does not affect the T cell functions directly.

Pesticide food poisoning from contaminated watermelons in California, 1985

Aldicarb, a carbamate pesticide, is the most potent pesticide in the market and has a LD50 of 1 mg/kg. In the United States it is illegal to use aldicarb on certain crops, e.g., watermelons, because it is incorporated into the flesh of the fruit. Once an accidental or illegal use of such a potent pesticide occurs, there is no easy way for the agricultural or public health system to protect the populace. This paper describes the impact of one such event upon the health of individuals and the institutions of California. On July 4, 1985, California and other western states experienced the largest known outbreak of food-borne pesticide illness ever to occur in North America. This was attributed to watermelons contaminated through the illegal or accidental use of aldicarb by a few farmers in one part of the state. Within California, a total of 1,376 illnesses resulting from consumption of watermelons was reported to the California Department of Health Services (CDHS). Of the 1,376 illnesses, 77% were classified as being probable or possible carbamate illnesses. Many of the case reports involved multiple illnesses associated with the same melon among unrelated individuals. Seventeen individuals required hospitalization. There were 47 reports of illness involving pregnant women, two of whom reported having subsequent stillbirths. Thirty-five of the remaining pregnant women were followed-up 9 mo after the epidemic; no additional stillbirths were found.(ABSTRACT TRUNCATED AT 250 WORDS)

Aldicarb food poisonings in California, 1985-1988: toxicity estimates for humans

Three outbreaks of food poisoning involving watermelons or cucumbers and caused by the carbamate pesticide aldicarb occurred in California between 1985 and 1988. For each outbreak, and for an outbreak of aldicarb poisoning associated with English cucumbers previously reported in the literature, dosages of aldicarb sulfoxide that caused the illnesses were estimated. Estimated dosages ranged between 0.0023 [corrected] and 0.06 mg/kg body weight, and most were well below the 0.025 mg/kg Lowest Observed Effect Level (LOEL) for subclinical blood cholinesterase depression previously reported for humans. These findings are consistent with aldicarb sulfoxide (ASO) illnesses that have occurred in other states. Aldicarb appears to be more toxic than previously suspected. Scientific and regulatory implications are discussed.

Aldicarb treatment inhibits the stimulatory activity of macrophages without affecting the T-cell responses in the syngeneic mixed lymphocyte reaction

Aldicarb, a carbamate pesticide used extensively throughout the United States, has been shown in several areas to contaminate drinking water at levels exceeding 100 p.p.b. Recent studies have suggested that aldicarb at levels well below these found in drinking water may lead to alterations in mammalian health. In the present study, we investigated the possible toxic effects of aldicarb on the mammalian immune system. Specifically examined in these studies were the effects of aldicarb on syngeneic mixed lymphocyte reaction (SMLR) in which CD4+ T-helper cells (autoreactive T-cells) respond to self or syngeneic Ia molecules expressed on macrophages. The effect of aldicarb was delineated at both the responder and stimulator cell-level. When C3H mice were injected intraperitoneally with a single dose of 0.1-1000 p.p.b. of aldicarb, it was observed that there was a decrease in the stimulatory functions of macrophages, as studied by decreased capacity to stimulate normal autoreactive T-cells. Further analysis revealed that the decreased stimulatory capacity of macrophages from aldicarb-treated mice was not due to decrease in the expression of Ia antigens, since flow cytometric analysis of macrophages from aldicarb-treated mice demonstrated normal levels of Ia expression. Also, cell-mixing experiments failed to demonstrate any suppressor macrophages in aldicarb treated mice. Addition of exogenous interleukin-1, however, completely reconstituted the defective stimulatory activity of macrophages from aldicarb-treated mice. In contrast to these effects on macrophages, it was observed that in C3H mice treated intraperitoneally with single dose of 1-1000 p.p.b. of aldicarb, there was no evidence of alteration in the ability of autoreactive T-cells to respond to syngeneic Ia molecules expressed on normal macrophages. In addition, responsiveness of T-lymphocytes obtained from aldicarb-treated mice to allogeneic Ia antigens was also unaltered. These data suggested that aldicarb may selectively suppress the stimulatory activity of macrophages by inhibiting IL-1 mediated signal to the T-cells without directly affecting the T-cell functions.

The environmental dynamics of the carbamate insecticide aldicarb in soil and water

Aldicarb is a soil-applied systemic pesticide the USEPA is now considering banning in the USA. Aldicarb is fairly rapidly oxidized to the sulfoxide, with a half-life of approximately 7 days in some soils, and much more slowly to the sulfone (pH-dependent with half-lives varying from a few minutes at a pH of > 12 to approximately 560 days at a pH of 6.0). Persistence, carry-over and translocation vary with soil and environmental conditions. Drainage aquifers and drinking water wells are known to be susceptible to contamination, levels of approximately 550 ppb have been recorded. Foods are also known to take up the pesticide; levels of 600 ppb have been found in potatoes.

Report of illnesses caused by aldicarb-contaminated cucumbers

During May and June of 1985 the Health Protection Branch and several other agencies were involved in the investigation of over 300 reports of illness reported in the Vancouver area of British Columbia, Canada. Symptoms reported included nausea, vomiting, dizziness, muscle fasciculation and blurred vision. A review of the onset of symptoms and food consumed suggested that at least 140 people had become ill from eating cucumbers adulterated with a carbamate pesticide. The presence of residues of aldicarb in cucumbers from one particular producer was confirmed by laboratory analysis.

Chromosomal aberrations in cultured human lymphocytes treated with aldicarb, a carbamate pesticide

Aldicarb was tested for its ability to induce chromosomal aberrations in human peripheral lymphocytes in vitro, in the presence of an exogenous metabolic activation system. The pesticide induced an increase in the number of chromatid and chromosome breaks. The increase was higher in the presence of S9 mix. A positive linear association between frequencies of abnormal cells and dose of aldicarb was observed.