Increased prevalence of the autism spectrum disorders (ASD) and the failure to find genetic explanations has pushed the hunt for environmental causes. These disorders are defined clinically but lack objective characterization.

 To meet this need, we measured neurobehavioral and pulmonary functions in eight ASD boys aged 8 to 19 years diagnosed clinically and compared them to 145 unaffected children from a community with no known chemical exposures. As 6 of 35 consecutive mold/ mycotoxin (mold)-exposed children aged 5 to 13 years had ASD, we compared them to the 29 non-ASD mold-exposed children, and to the eight ASD boys. Comparisons were adjusted for age, height, weight, and grade attained in school. 

The eight ASD boys averaged 6.8 abnormalities compared to 1.0 in community control boys. The six mold-exposed ASD children averaged 12.2 abnormalities. The most frequent abnormality in both groups was balance, followed by visual field quadrants, and then prolonged blink reflex latency. 

Neuropsychological abnormalities were more frequent in mold-exposed than in terbutaline-exposed children and included digit symbol substitution, peg placement, fingertip number writing errors, and picture completion. Profile of mood status scores averaged 26.8 in terbutaline-exposed, 52 in mold exposed, and 26 in unexposed. The mean frequencies of 35 symptoms were 4.7 in terbutaline, 5.4 in mold/ mycotoxins exposed and 1.7 in community controls. 

Reference:   Kilburn KH, Thrasher JD, Immers NB., Do terbutaline- and mold-associated impairments of the brain and lung relate to autism?, Toxicol Ind Health. 2009 Sep 30.

Neurobehavioral and pulmonary impairment in 105 adults with indoor exposure to molds compared to 100 exposed to chemicals 

Patients exposed at home to molds and mycotoxins and those exposed to chemicals (CE) have many similar symptoms of eye, nose, and throat irritation and poor memory, concentration, and other neurobehavioral dysfunctions. Aim of a study was to compare the neurobehavioral and pulmonary impairments associated with indoor exposures to mold and to chemicals. 

105 consecutive adults exposed to molds (ME) indoors at home and 100 patients exposed to other chemicals were compared to 202 community referents without mold or chemical exposure. To assess brain functions, the scientists measured 26 neurobehavioral functions. Medical and exposure histories, mood states score, and symptoms frequencies were obtained. Vital capacity and flows were measured by spirometry. Groups were compared by analysis of variance (ANOVA) after adjusting for age, educational attainment, and sex, by calculating predicted values (observed/predicted x 100 = % predicted). And p < .05 indicated statistical significance for total abnormalities, and test scores that were outside the confidence limits of the mean of the percentage predicted. 

People exposed to mold had a total of 6.1 abnormalities and those exposed to chemicals had 7.1 compared to 1.2 abnormalities in referents. Compared to referents, the exposed groups had balance decreased, longer reaction times, and blink reflex latentcies lengthened. Also, colour discrimination errors were increased and visual field performances and grip strengths were reduced. The cognitive and memory performance measures were abnormal in both exposed groups. Culture Fair scores, digit symbol substitution, immediate and delayed verbal recall, picture completion, and information were reduced. Times for peg-placement and trail making A and B were increased. 

One difference was that chemically exposed patients had excess fingertip number writing errors, but the mold-exposed did not. Mood State scores and symptom frequencies were greater in both exposed groups than in referents. Vital capacities were reduced in both groups. Neurobehavioral and pulmonary impairments associated with exposures to indoor molds and mycotoxins were not different from those with various chemical exposures. 

Reference: Kilburn KH, Neurobehavioral and pulmonary impairment in 105 adults with indoor exposure to molds compared to 100 exposed to chemicals, University of Southern California, Keck School of Medicine (ret.), Pasadena, CA, USA., Toxicol Ind Health. 2009 Sep 30.

Chemicals and Molds often associated with Sick Building Syndrome   

A study was performed to explore possible environmental risk factors, including indoor chemicals, mold, and dust mite allergens, which could cause sick building syndrome (SBS)-type symptoms in new houses. 

The study was conducted in 2004 and 2005 and the final study population consisted of 86 men and 84 women residing in Okayama, Japan. 

The indoor concentrations of indoor aldehydes, volatile organic compounds, airborne fungi, and dust mite allergens in their living rooms were measured and the longitudinal changes in two consecutive years were calculated. 

A standardized questionnaire was used concomitantly to gather information on frequency of SBS-type symptoms and lifestyle habits. About 10% of the subjects suffered from SBS in the both years. 

Crude analyses indicated tendencies for aldehyde levels to increase frequently and markedly in the newly diseased and ongoing SBS groups. Among the chemical factors and molds examined, increases in benzene and in Aspergillus contributed to the occurrence of SBS in the logistic regression model. 

Indoor chemicals were the main contributors to subjective symptoms associated with SBS. A preventive strategy designed to lower exposure to indoor chemicals may be able to counter the occurrence of SBS. 

Reference:  Takigawa T, Wang BL, Sakano N, Wang DH, Ogino K, Kishi R.,    A longitudinal study of environmental risk factors for subjective symptoms associated with sick building syndrome in new dwellings, Sci Total Environ. 2009 Sep 15;407(19):5223-8.

To examine the effects of solvent exposure on hearing function, through an audiological test battery, in a population not occupationally exposed to high levels of noise. 

One hundred ten workers from a coating factory were studied. Jobs at the factory were divided into three different levels of solvent exposure. Hearing status was assessed with a test battery including pure-tone hearing thresholds (0.5-8 kHz), high-frequency hearing thresholds (12 and 16 kHz), and dichotic listening measured through dichotic digits test. Multiple linear regression models were created to explore possible association between solvent exposure and each of the hearing outcomes. 

Significant associations between solvent exposure and the three hearing outcomes were found. Covariates such as age, gender, race, and ethnicity were also significantly associated with the studied hearing outcomes. 

Occupational exposure to solvents may induce both peripheral and central auditory dysfunction. The dichotic digits test seems as a sensible tool to detect central auditory dysfunction associated with solvent exposure. Hearing loss prevention programs may use this tool to monitor hearing in solvent-exposed workers. 

Reference:   Fuente A, Slade MD, Taylor T, Morata TC, Keith RW, Sparer J, Rabinowitz PM., Peripheral and Central Auditory Dysfunction Induced by Occupational Exposure to Organic Solvents, J Occup Environ Med. 2009 Sep 25 

From the Escuela de Fonoaudiologia [School of Speech and Hearing Sciences] (Dr Fuente), Medical Faculty, Universidad de Chile, Santiago, Chile; Occupational and Environmental Medicine Program (Mr Slade, Dr Taylor, Ms Sparer, and Dr Rabinowitz), Yale University School of Medicine, New Haven, Conn; Division of Applied Research and Technology (Dr Morata), National Institute for Occupational Safety and Health; and Division of Audiology (Dr Keith), University of Cincinnati, Cincinnati, Ohio.