There is increasing concern about the effects of pile driving and other anthropogenic (human-generated) sound on fishes. Although there is a growing body of reports examining this issue, little of the work is found in the peer-reviewed literature. This review critically examines both the peer-reviewed and 'grey' literature, with the goal of determining what is known and not known about effects on fish. A companion piece provides an analysis of the available data and applies it to estimate noise exposure criteria for pile driving and other impulsive sounds. The critical literature review concludes that very little is known about effects of pile driving and other anthropogenic sounds on fishes, and that it is not yet possible to extrapolate from one experiment to other signal parameters of the same sound, to other types of sounds, to other effects, or to other species.

The effects of anthropogenic sources of sound on fishes.

The pathology of primary blast overpressure injury

Traumatic brain injury caused by explosive or blast events is traditionally divided into four phases: primary, secondary, tertiary, and quaternary blast injury. These phases of blast-induced traumatic brain injury (bTBI) are biomechanically distinct and can be modeled in both in vivo and in vitro systems. The primary bTBI injury phase represents the response of brain tissue to the initial blast wave. Among the four phases of bTBI, there is a remarkable paucity of information about the cause of primary bTBI. On the other hand, 30 years of research on the medical application of shockwaves (SW) has given us insight into the mechanisms of tissue and cellular damage in bTBI, including both air-mediated and underwater SW sources. From a basic physics perspective, the typical blast wave consists of a lead SW followed by supersonic flow. The resultant tissue injury includes several features observed in bTBI, such as hemorrhage, edema, pseudoaneurysm formation, vasoconstriction, and induction of apoptosis...

Mechanisms of Primary Blast-Induced Traumatic Brain Injury: Insights from Shock-Wave Research

OBJECTIVES:: Existing experimental approaches for studies of blast impact in small animals are insufficient and lacking consistency. Here, we present a comprehensive model, with repeatable blast signatures of controlled duration, peak pressure, and transmitted impulse, accurately reproducing blast impact in laboratory animals. MATERIALS:: Rat survival, brain pathomorphology, and levels of putative biomarkers of brain injury glial fibrillary acid protein (GFAP), neuron-specific enolase, and ubiquitin C-terminal hydrolase (UCH)-L1 were examined in brain, cerebrospinal fluid (CSF), and blood after 10 msec of 358 kPa peak overpressure blast exposure. RESULTS:: The high-speed imaging demonstrated a strong head acceleration/jolting accompanied by typical intracranial hematomas and brain swelling. Microscopic injury was revealed by prominent silver staining in deep brain areas, including the nucleus subthalamicus zone, suggesting both diffused and focal neurodegeneration. GFAP and 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase), markers of astroglia and oligodendroglia, accumulated substantially in the hippocampus 24 hours after blast and persisted for 30 days postblast. However, GFAP content in the blood significantly increased 24 hours after injury, followed by a decline and subsequent accumulation in CSF in a time-dependent fashion. A similar profile is shown for UCH-L1 increase in blood, whereas increased CSF levels of UCH-L1 persisted throughout 14 days after blast and varied significantly in individual rats. Neuron-specific enolase levels in blood were significantly elevated within 24 hours and 48 hours postblast. CONCLUSIONS:: The proposed model of controlled nonpenetrating blast in rats demonstrates the critical pathologic and biochemical signatures of blast brain injury that may be triggered by cerebrovascular responses, including blood-brain barrier disruption, glia responses, and neuroglial alterations. Language: en

Morphologic and Biochemical Characterization of Brain Injury in a Model of Controlled Blast Overpressure Exposure

Head injury remains one of the most frequent and severe injuries sustained by vehicle occupants, motorcyclists, pedestrians and cyclists in road accidents and account for approximately 40% of road fatalities in the European Union (EU). One essential requirement for reducing the incidence of fatal and severe head injuries is to develop head injury assessment methods that can accurately and comprehensively assess the potential head injury risk under a broad range of head impact conditions. At present, the most widely accepted method of assessing head injury risk in road safety research is the Head Injury Criterion (HIC). However, HIC only considers the injury risk to the head resulting from linear head accelerations. In an attempt to develop improved head injury criteria for specific mechanisms, 68 head impact conditions that occurred in motor sport, motorcyclist, American football and pedestrian accidents were re-constructed with a state of the art finite element (FE) human head model (ULP head model). Sta...

Improved head injury criteria based on head FE model

A model of blast overpressure injury to the lung

Four impulse noise auditory injury criteria adopted by NATO countries, namely, the MIL-STD-1474D (USA), Pfander (Germany), Smoorenburg (Netherlands), and LAeq8 (France), are evaluated against human volunteer data. Data from subjects wearing single-hearing protection exposed to increasing blast overpressure effects were obtained from tests sponsored by the US Army Medical Research and Material Command. Using logistic regression, the four criteria were each correlated with the test data. The analysis shows that all four criteria are overly conservative by 9.6–21.2 dB for the subjects as tested. The MIL-STD-1474D for single-hearing protection is 9.6 dB lower than the observed injury threshold for 95% protection with 95% confidence for this particular group of subjects as tested. Similar conclusions can be drawn for the other three criteria.

Evaluation of impulse noise criteria using human volunteer data.

This work developed a skull fracture criterion for impact-induced head injury, using post mortem human subject tests, anatomical test device measurements, statistical analyses, and finite element modeling. It is shown that skull fracture correlates with the tensile strain in the outer table of the cranial bone, and an index termed the Skull Fracture Correlate (SFC) predicts injury. SFC offers several advantages as a protection criterion. It accounts for compliance of the impact site; it is extensible to varying head mass; and it is easily implemented using current software. For a 15% or less probability of skull fracture the criterion is SFC < 120 g, with a 95% confidence band of 88 < SFC < 135 g.

Statistically and biomechanically based criterion for impact-induced skull fracture.

Impulse noise injury prediction based on the cochlear energy.

Objectives: The new Auditory 4.0 model has been developed for the assessment of auditory outcomes, expressed as temporary threshold shift (TTS) and permanent threshold shift (PTS), from exposures to impulse noise for unprotected ears, including the prediction of TTS recovery. Methods: Auditory 4.0 is an empirical model, constructed from test data collected from chinchillas exposed to impulse noise in the laboratory. Injury outcomes are defined as TTS and PTS, and Auditory 4.0 provides the full range of TTS and PTS dose–response curves with the risk factor constructed from A-weighted sound exposure level. Human data from large weapons noise exposure was also used to guide the development of the recovery model. Results: Guided by data, a 28-dBA shift was applied to the dose–response curves to account for the scaling from chinchillas to humans. Historical data from rifle noise tests were used to validate the dose–response curves. New chinchilla tests were performed to collect recovery data to constr...

Kevin Ho

Papers

A model of blast overpressure injury to the lung

Evaluation of impulse noise criteria using human volunteer data.

Statistically and biomechanically based criterion for impact-induced skull fracture.

Impulse noise injury prediction based on the cochlear energy.

Impulse Noise Injury Model