Follow-up study of cancer incidence after chlorophenol exposure in a community in southern Finland.

OBJECTIVES: In the 1970s and 1980s, people in a village in southern Finland had been exposed to high concentrations of chlorophenols in the drinking water and in fish from a nearby lake. An ecological analysis and a case-control study conducted around 1990 indicated significant excess in the incidence of non-Hodgkin's lymphoma and soft-tissue cancer in the municipality and a relationship between the chlorophenol exposure and the incidence of these cancers. The present article reports a follow-up of cancer risk in the same study area during a 20-year period after the closing of the old water intake plant, which was contaminated by chlorophenols. METHODS: The observed and expected numbers of cancer were obtained for three periods, 1953-1971 (before exposure), 1972-1986 (during exposure) and 1987-2006 (after exposure), for all cancers combined and separately for cancers potentially related to chlorophenols. RESULTS: The present study demonstrates that all of the cancer risks returned to the average population level during the 20-year period after the old water intake plant was closed and chlorophenol exposure stopped. CONCLUSIONS: The rapid changes in cancer risk after changes in chlorophenol exposure suggest that chlorophenols may have a promotion effect in the carcinogenic process.

Birth malformations and other adverse perinatal outcomes in four U.S. Wheat-producing states.

Chlorophenoxy herbicides are widely used in the United States and Western Europe for broadleaf weed control in grain farming and park maintenance. Most of the spring and durum wheat produced in the United States is grown in Minnesota, Montana, North Dakota, and South Dakota, with more than 85% of the acreage treated with chlorophenoxy herbicides such as 2,4-dichlorophenoxyacetic acid (2,4-D) and 4-chloro-2-methylphenoxyacetic acid (MCPA). Rates of adverse birth outcomes in rural, agricultural counties of these states during 1995-1997 were studied by comparing counties with a high proportion of wheat acreage and those with a lower proportion. Information routinely collected and made available by federal agencies was used for this ecologic study. Significant increases in birth malformations were observed for the circulatory/respiratory category for combined sexes [odds ratio (OR) = 1.65; 95% confidence interval (CI), 1.07-2.55]. A stronger effect was observed for the subcategory, which excluded heart malformations (OR = 2.03; 95% CI, 1.14-3.59). In addition, infants conceived during April-June--the time of herbicide application--had an increased chance of being diagnosed with circulatory/respiratory (excluding heart) malformations compared with births conceived during other months of the year (OR = 1.75; 95% CI, 1.09-2.80). Musculoskeletal/integumental anomalies increased for combined sexes in the high-wheat counties (OR = 1.50; 95% CI, 1.06-2.12). Infant death from congenital anomalies significantly increased in high-wheat counties for males (OR = 2.66; 95% CI, 1.52-4.65) but not for females (OR = 0.48; 95% CI, 0.20-1.15). These results are especially of concern because of widespread use of chlorophenoxy herbicides.

[Prophylactic efficiency of tietasol and oxymethyluracyl against chlorphenols exposure in experimental and real conditions]. / Profilakticheskaia éffektivnost' tietazola i oksimetiluratsila pri vozdeistvii khrorfenolov.

The authors studied protective efficiency of tietasol and oxymethyluracyl in experiments with animals exposed to 2,4-dichlorphenol and in real chlorphenol production. According to the results, oxymethyluracyl could be recommended to increase resistance against chemicals in occupational conditions.

Occupational fatalities associated with 2,4-dichlorophenol (2,4-DCP) exposure, 1980-1998.

2,4-Dichlorophenol (2,4-DCP) is a feedstock chemical primarily used to produce the herbicide 2,4-dichloropheoxyacetic acid (2,4-D). In October 1998, the U.S. Environmental Protection Agency (EPA) was notified of the death of a worker acutely exposed to 2,4-DCP. Follow-up investigation by EPA, the Occupational Safety and Health Administration (OSHA), and CDC's National Institute for Occupational Safety and Health (NIOSH) identified four earlier deaths associated with acute 2,4-DCP exposure, which occurred during 1980-1992. All of these incidents resulted in rapid death after dermal exposure to the heated liquid form of the chemical. This report describes the five deaths associated with 2,4-DCP exposure (presented in the order in which they were identified) and provides recommendations for preventing additional deaths.

[Medical consequences of drinking water pollution resulting from a chemical accident]. / Meditsinskie posledstviia zagriazneniia pitévoi vody vsledstvie khimicheskoi avarii.

The article describes consequences of the chemical accident in Ufa, lead to the drinkable water pollution by phenol and chlorophenolic compounds. Events required the prompt prophylactic measures and reconstruction of health care in the city. The treatment tactics approved at that period of time are represented.

Accidental death caused by the absorption of 2,4-dichlorophenol through the skin.

A case involving an accidental fatality resulting from skin absorption of 2,4-dichlorophenol in a factory is presented. The compound was quantified using gas chromatography after separation on a SP-1240 DA column and detection with flame ionization. Confirmation was obtained with mass spectrometry. Blood concentration was 24.3 mg/l. Other drugs, including ethanol, were not detected.

Association between soft tissue sarcomas, malignant lymphomas, and phenoxy herbicides/chlorophenols: evidence from occupational cohort studies.

Some case-control studies have reported a significant association between occupational use of phenoxy herbicides and chlorophenols and soft-tissue sarcomas and malignant lymphomas. However, persons who spray or apply these substances are concomitantly exposed to other potentially carcinogenic chemicals and oncogenic viruses, which have been found or suspected to play a role in the etiology of these tumors. No study has thoroughly controlled for these other exposures, some of which have been shown to be independently associated with these tumors even after controlling for exposure to phenoxy acids or chlorophenols. On the other hand, it has been found that an observed risk from exposure to phenoxy herbicides disappeared on controlling for some of these concomitant exposures in the rare instance this was attempted. Also, on several occasions, an association has been observed with occupations in which exposure to phenoxys and chlorophenols may occur, but not with the compounds themselves. Accordingly, a detailed review of the evidence from occupational cohort studies was conducted, to see if it corroborates that from case-control studies. It was found that the evidence does not unequivocally incriminate phenoxys and chlorophenols as a cause of these tumors. The results obtained with cohort studies of sprayers and applicators do not corroborate the association reported among this occupational group, in case-control studies. It is possible that the suspected association may well be due, partly or wholly, to one or more of the other concomitant exposures. However, in view of the fact that the majority of the cohorts need further follow-up to be informative, it is concluded that further studies of these cohorts are required before it can be determined whether or not these tumors are caused by exposure to phenoxy acids and chlorophenols.

Aplastic anaemia associated with organochlorine pesticide: case reports and review of evidence.

Three patients with aplastic anaemia had a history of substantial previous exposure to organochlorine pesticides. The temporal association between chemical exposure and the onset of first symptoms of anaemia was strongly supportive. Organochlorines have the property of lipid affinity and accumulation in adipose tissue. Objective evidence of clinically important concentrations of tissue pesticide residues may be a useful confirmation of previous exposure. In the patients studied the presence of Lindane (gamma hexachlorocyclohexane) was shown using gas chromatography/mass spectrometry with selective ion monitoring of fragments obtained from one heavily exposed patient, with concentrations about five times greater than a matched control. The presence of clinically important tissue concentrations of pentachlorophenol was also confirmed in a second patient exposed to this agent. The long term safety of organochlorine pesticides remains doubtful as they were introduced before adequate toxicological screening tests had been developed. The central registration of possible haematological adverse reactions, however, forms an important epidemiological method in the study of environmental chemical hazards and should be complied with whenever possible.

Validity and reliability of a method for retrospective evaluation of chlorophenate exposure in the lumber industry.

This paper describes the validity and reliability of a method to retrospectively assess exposure to antisapstain agents used in sawmills (chlorophenates). The method is based on experienced workers' estimates of exposure for each job title at the sawmill where they work. At a pilot mill, 10 randomly selected workers estimated the frequency and duration of exposures to chlorophenates for all 59 job titles. The reliability of their mean exposure estimates was very high, with an intraclass correlation coefficient for all raters of 0.91 (based on a calculated index of exposure). To assess validity, urinary chlorophenate levels were measured for 86% of the workers at the mill during the summer and/or fall, and compared to experienced workers' estimates of exposure. The correlation between workers' exposure estimates and the urinary chlorophenate levels for each job title were consistently above 0.65 for all analyses and greater than 0.72 when summer and fall urine sample results were averaged. The evidence indicates that the validity and reliability of worker exposure estimates are high enough to justify investigation of the method's generalizability to other sawmills.

Health effects of phenoxy herbicides. A review.

A review of epidemiological studies on the health effects of exposure to phenoxy herbicides suggests that exposure may be associated with an increased incidence of cancer and unfavorable outcomes of pregnancy. Studies on cancer have found increased risks of 5.3, 6.8 and 3.96 for soft-tissue sarcoma, 7.7 and 6.0 for stomach cancer, 2.05 for lung cancer, 4.8 for lymphoma, 2.3 for all cancers combined, and 5.2 for liver cancer after exposure to 2,4,5-T or dioxin contaminants. Several studies have suggested a possible increase in birth defects after paternal exposure. An increased risk of hydatidiform mole is suggested by Vietnamese studies on the effects of maternal exposure.

Occupational exposure to chlorophenates. Renal, hepatic and other health effects.

A group of 71 chlorophenate-exposed sawmill workers were identified as part of a group undergoing an extensive health and environmental evaluation in a pulp mill. This group was compared with a group (N = 351) with no physical proximity to the area in which chlorophenates were used. Exposure was higher for those directly handling the wood and lower for those working in the area but not handling the wood. Those with chlorophenate exposure were not significantly more likely to report a history of jaundice or liver, kidney or heart disease. Moreover, the serum creatinine, bilirubin, glutamic oxaloacetic transaminase (GOT), and alkaline phosphatase values did not differ from those of the reference group. The hemoglobin level was similar in the three groups. But the peripheral blood leukocyte count was marginally lower in the exposed groups and their hematocrit was reduced, significantly so for the heavily exposed group. Urinalysis showed an increased prevalence of microscopic hematuria, especially with lower cell counts. No unequivocal explanation is available for the reduced hematocrit or the low level of hematuria.

Pentachlorophenol intoxication: report of a fatal case, with comments on the clinical course and pathologic anatomy.

A case of a 33-yr-old man who died following occupational exposure to pentachlorophenol is presented. Postmortem examination revealed cerebral edema and fatty degeneration of the viscera. Review of the literature indicates that the clinical syndrome of poisoning with the compound results from mitochondrial toxicity with derangement of aerobic metabolism.

Pentachlorophenol poisoning.

Pentachlorophenol (PCP) is a pesticide commonly used as a wood preservative. Although exposure has been well controlled in large chemical manufacturing plants, over-exposures have recently becomes a concern at smaller facilities. Five cases of PCP poisoning, including two fatalities, occurred in two small wood preservative plants. All cases presented with fever, including severe hyperpyrexia in two; an increased anion gap and renal insufficiency were noted in two others. PCP may uncouple oxidative phosphorylation, resulting in a poisoning syndrome characterized by hyperpyrexia, diaphoresis, tachycardia, tachypnea, abdominal pain, nausea, and even death.